Be STAR NEWSLETTER

ISSN 0296-3140

Be STAR NEWSLETTER

NUMBER 40 - August 2012

Editor-in-Chief: Technical Editor: Webmaster: Geraldine J. Peters Douglas R. Gies David McDavid e-mail: [email protected] e-mail: [email protected] e-mail: [email protected] Space Sciences Center Center for High Angular Resolution Astronomy Department of Astronomy University of Southern California Department of Physics and Astronomy University of Virginia University Park Georgia State University PO Box 400325 Los Angeles CA 90089-1341 Atlanta GA 30303-3083 Charlottesville VA 22904-4325 Tel: (213) 740-6336 Tel: (404) 413-6021 Tel: (434) 924-7494 FAX: (213) 740-6342 FAX: (404) 413-5481 FAX: (434) 924-3104

Contents

1 Editorial – G. Peters 3

2 Working Group Matters 4 2.1 Meeting of the Working Group on Active B Stars at the 27th IAU General Assembly in Rio de Janeiro, Brazil: Call for Contributed Talks – Gerrie Peters & Juan Fabregat ...... 4 2.2 Division IV-V / Working Group Active B-Type Stars: Triennial Report 2006- 2009 – Juan Fabregat & Geraldine J. Peters ...... 4 2.3 Business Meeting and Scientiﬁc Session of the Working Group on Active B Stars 27th IAU General Assembly, Rio de Janeiro, Brazil August 6, 2009 – G. J. Peters ...... 7 2.4 Proposal for the Bylaws for the IAU Working Group on Active B Stars – G. J. Peters ...... 7 2.5 PROCEEDINGS: Business Meeting of the Working Group on Active B Stars 27th IAU General Assembly, Rio de Janeiro, Brazil August 6, 2009 – Geraldine J. Peters ...... 9 2.6 Greetings from the Chair of the Working Group – Gerrie Peters ...... 13 2.7 Thoughts from the Outgoing Chair of the Working Group – Juan Fabregat 13 2.8 Call for Presentations at the IAU GA in Beijing – Gerrie Peters ...... 14 2.9 WGABS Meeting at the IAU GA in Beijing – Gerrie Peters ...... 15 2.10 SOC Election 2012: IAU WORKING GROUP on ACTIVE B STARS – Gerrie Peters & David McDavid ...... 15 2.11 Division IV-V / Working Group Active B-Type Stars: Triennial Report 2009- 2012 – Geraldine J. Peters & Carol E. Jones ...... 16 2.12 Updated Working Group Bylaws Approved by SOC – David McDavid . . . 20

3 Scientiﬁc Program, Working Group on Active B Stars, IAU 27th General Assembly 22 3.1 Inﬂuence of X-ray radiation on wind structure of hot stars – J. Krtiˇcka . . . 22 3.2 Active B stars and the new class of “gamma-ray binaries”? – V. McSwain . 22 3.3 Non-radial pulsations in the open cluster NGC 3766 – R. Roettenbacher . . 25 3.4 Analysis of B and Be star populations of the double cluster h and χ Persei – A. Marsh ...... 27

4 What’s Happening? 32 4.1 A new bright outburst of the Be star mu Centauri – Sebasti´anA. Otero . . 32

2012, Be Star Newsletter, 40 − 1 4.2 IAU Symposium 272: “Active OB stars: structure, evolution, mass loss, and critical limits” (First Announcement) – C. Neiner ...... 33 4.3 Post-doc position in observational studies of massive stars at Universidad de Valparaiso, Chile – Michel Cure ...... 34 4.4 JOB OFFER FOR 2 PERMANENT POSITIONS: University of Guanajuato – Philippe Eenens ...... 34 4.5 Announcement: Kick-off of GREAT working group on Stellar Variability with Gaia – Joris de Ridder ...... 36 4.6 Periodic behavior of the He I 6678 emission in δ Sco – Ernst Pollmann . . . 36 4.7 Research Position at the Stellar Department Ondrejov – Jiˇr´ıKubát. . . . . 40 4.8 IAU Symposium 272: “Active OB stars: structure, evolution, mass loss, and critical limits” (Final Announcement) – C. Neiner ...... 40 4.9 Post-doctoral Position at the University of SãoPaulo, Brazil – Alex C. Carciofi 41 4.10 The end of an active Be state in 66 Oph – A. S. Miroshnichenko, S. V. Zharikov, J. Fabregat, D. E. Reichart, K. M. Ivarsen, J. B. Haislip, M. C. Nysewander, and A. P. LaCluyze ...... 42 4.11 Post-doctoral position in B[e] star research – Michaela Kraus ...... 44 4.12 Hα Spectroscopy and V Variations of Be Star 28 Tauri (Pleione) – Ernst Pollmann ...... 45 4.13 Ca II K line profile in the latest Be-epoch of Pleione – Jun-ichi Katahira, Kazutoshi Inoue, Yoshihito Kawabata, and Tetuya Kawabata ...... 48 4.14 Workshop: “Circumstellar Dynamics at High Resolution” (First Announce- ment) – Alex Carciofi ...... 52 4.15 Workshop: “Circumstellar Dynamics at High Resolution” (Last Announce- ment) – Alex Carciofi ...... 54 4.16 First Announcement: 11th Hvar Astrophysical Colloquium – Domagoj Ruzdjak 55 4.17 Long bright outburst of the Be star µ Cen – SebastiánA. Otero ...... 56

5 Abstracts 59

6 Meetings 85

7 LaTeX Template for Abstracts 85

Cover illustration: Logo for IAU Symposium No. 272 (Active OB Stars: Structure, Evolu- tion, Mass-Loss, and Critical Limits) held in Paris, France from 2010 July 19-23.

The Be Star Newsletter is produced at and ﬁnancially supported by the Georgia State University Department of Physics and Astronomy. The electronic version is hosted by the University of Virginia Department of Astronomy and is available on the World Wide Web at http://www.astro.virginia.edu/∼dam3ma/benews/.

2012, Be Star Newsletter, 40 − 2 1. EDITORIAL

We are pleased to finalize Issue No. 40 of the Be Star Newsletter. Following our recent practice we assemble an issue after we have accumulated about 50–60 pages of material on our website. The Newsletter continues to be organized in the following sections: Working Group Matters, What’s Happening, Abstracts, and information on meetings of interest to the active B star community. Issue No. 40 contains more than fifteen items in What’s Happening and forty abstracts of published papers. In Working Group Matters we include the proceedings from the meeting of the Working Group on Active B stars that was held in Rio de Janeiro, Brazil in August 2009. It was at this meeting that the by-laws for the Working Group were finally formalized. Research interests of the Working Group members are summarized in the triennial reports for 2006– 09 and 2009–12. Our understanding of the activity in B stars, including the Be phenomenon continues to deepen. From high-resolution interferometry to state-of-the-art modeling codes researchers are learning more about the nature of Be star disks. The MiMeS (Magnetism in Massive Stars) collaboration is revealing important information on the origin of magnetic fields in B stars and their role in generating short-term activity and controlling evolution. The Kepler, CoRoT, and MOST spacecraft continue to produce high-quality photometry over long baselines in time. Combined with spectroscopic data these observations reveal a rich set of pulsational frequencies and modes from which constraints can be placed on the internal rotation, metallicity, and the nature of sub-photospheric convection. The high point of the past triennium was IAU Symposium No. 272 (Active OB Stars: Struc- ture, Evolution, Mass-Loss, and Critical Limits) held in Paris, France from 2010 July 19–23. The editors of the Newsletter would like to thank Coralie Neiner for this very successful and enjoyable meeting. Congratulations Coralie! Since traditionally the cover graphic of the Newsletter has been either a novel observation, new theoretical model, or an illustration representing the pulse of contemporary research, the logo for IAUS 272 seemed to be a natural for Issue No. 40. It was great to see and talk with so many colleagues at this meeting. The editors wish to thank all who contributed to this issue. We continue to post short articles and abstracts on our website as they are accepted (http://www.astro.virginia.edu/∼dam3ma/benews/). Please send new contributions by email to [email protected]. We prefer LaTeX format and require that abstracts be submitted as a LaTeX file using the template provided on our website. We encourage you to contribute to our Community Comments section that we introduced in Issue No. 38. In an open forum researchers have the opportunity to voice their opinions on scientific issues and terminology that will become part of the published literature such as one finds in unedited discussion in conference proceedings. We appreciate the continuing support from the Department of Physics & Astronomy at Georgia State University for the production of the paper edition of the Be Star Newsletter. Gerrie Peters, Editor-in-Chief

2012, Be Star Newsletter, 40 − 3 2. WORKING GROUP MATTERS

2.1. Meeting of the Working Group on Active B Stars at the 27th IAU General Assembly in Rio de Janeiro, Brazil: Call for Contributed Talks The Working Group on Active B stars has been allocated three hours (2 sessions) for a business and scientific meeting at the forthcoming IAU General Assembly in Rio de Janeiro. The meeting is scheduled from 09:00–10:30 and 11:00–12:30 on Thursday, August 6, 2009. The IAU GA will be held in the new SulAméricaConvention Center. Our room assignment will announced in May. As usual the business meeting should be short, leaving nearly 2.5 hours for scientific talks. If you would like to present a talk during this meeting, please send us a title for your presentation ASAP. We welcome longer, research-oriented talks as well as brief announcements or updates on current activities of interest to the Working Group members. We envision presentations lasting from 5–30 minutes, including discussion. We plan to publish the proceedings of the business and scientific meetings in the Be Star Newsletter. Please submit your title and the requested time for your presentation to: [email protected]. Note that early on-line registration for the IAU GA ends on May 1. We are looking forward to seeing you in Rio in August.

Breaking News

The IAU has just announced that our proposal to hold a symposium on active OB stars in Paris in mid-July of 2010 has been accepted, so please SAVE THE DATE! IAU S272 “Active OB stars: structure, evolution, mass loss, and critical limits” will take place from 2010 July 19-23. The chair of the SOC is Coralie Neiner. More information will follow after the website becomes active.

Gerrie Peters Juan Fabregat

2.2. Division IV-V / Working Group Active B-Type Stars: Triennial Report 2006-2009

CHAIR Juan Fabregat and Geraldine J. Peters PAST CHAIR Stanley P. Owoki BOARD Karen S. Bjorkman, Douglas R. Gies, Hubertus F. Henrichs, David McDavid, Coralie Neiner, Philippe Stee

TRIENNIAL REPORT 2006-2009

2.2.1. Introduction

The Working Group on active B-type stars (formerly known as the Working Group on Be Stars) was re-established under IAU Commission No. 29 at the IAU General Assembly in Montreal, Quebec, Canada in 1979, and has been continuously active to the present. Its

2012, Be Star Newsletter, 40 − 4 main goal is to promote and stimulate research and international collaboration on the ﬁeld of the active early-type (OB) stars. The interest of the WG were originally focused on classical Be stars research. The recent years have seen a broadening of the group interests, with an increasing contact and overlap with other research areas, particularly for closely aligned topics like pulsating OB stars.

2.2.2. Developments within the past triennium

The Be Star Newsletter 1 has continued to be the main source of information on new discoveries, ideas, manuscripts, and meetings on active B stars. G. Peters, D. Gies, and D. McDavid continue, respectively, as Editor-in-Chief, Technical Editor, and Webmaster. The issue No. 38 was published in March 2007, and contains, among other items, 18 notes and advertisments of interest for the active B stars community and 36 abstracts of papers relevant to its research subjects. The current working issue No. 39 contains 6 research notes and 18 abstracts as of June 30th. The proceedings of the last major meeting on active B stars, “Active OB-Stars: Laboratories for Stellar and Circumstellar Physics”, held in Sapporo, Japan, were published in March 2007 (Okazaki, Owocki & Steflˇ 2007). In general grounds, the field of the Be star research has been very active during the last few years, and we expect this activity to increase. The recent development of powerful observational equipment has led to significant progress in our knowledge of active B stars physics. The advent of the VLTI interferometer and the CHARA Array have allowed the spatial resolution of several Be star photospheres and disks (e.g. Domiciano de Souza et al. 2003; Gies et al. 2007), and the finding of the Keplerian rotation in the disk around α Arae (Meilland et al. 2007). The application of spectropolarimetric techniques resulted in the discovery of magnetic fields in a few Be stars (Neiner et al. 2003), and the commissioning of new and more powerful spectropolarimeters will allow the systematic study of the prevalence of magnetic fields among Be stars and their relation with the mass ejection episodes. Perhaps the most exciting current development is the accurate photometric monitoring of Be stars from outside our atmosphere. The Canadian space mission MOST, launched on 2003 June 30, has already provided photometric time series of unprecedented quality of several bright Be stars, revealing a rich spectrum of frequencies associated with radial and nonradial pulsations (Walker et al. 2005a,b; Saio et al. 2007; Cameron et al. 2008). The French led COROT satellite was successfully launched on December 2006, and started its scientific observations on 2007 February 3rd. COROT is providing photometry of many B and Be stars in continuous runs lasting from 20 to 150 days. The analysis of the photometric time series and the interpretation of the results with the techniques of asteroseismology will provide important insights on the internal structure of Be stars, the role of nonradial pulsations, and its relation with the Be star outbursts (Michel et al. 2006). Although opportunities to study Be stars in the FUV are currently limited, new spectra were recently obtained of Be stars in our galaxy and the Magellanic Clouds with the FUSE spacecraft. This new data will provide information on the abundances of carbon, nitrogen, and the iron group elements in the photospheres of Be stars that will complement and serve as a check on the results and predictions from the planned asteroseismology investigations

1http://www.astro.virginia.edu/∼dam3ma/benews/

2012, Be Star Newsletter, 40 − 5 as well as theories for Be stars based upon the concept of critical rotation. The rapid rotation of Be stars may be caused in some cases by past mass and angular momentum accretion in an interacting binary. The mass donor would currently appear as a hot subdwarf, stripped of its outer envelope and N-rich as the CNO-processed core is now exposed. Recently the presence of a subdwarf companion to the Be star FY CMa was detected (Peters et al. 2008, ApJ, Oct. 10 issue, in press) and thus this bright Be star becomes the second confirmed example, after φ Per, of a Be + sdO system. Other important tools that will be available for Be star researchers in the near future are the ongoing and planned deep photometric galactic plane surveys. In the northern hemisphere the Hα IPHAS survey (Drew et al. 2005) and the near-infrared UKIDSS-GPS survey (Lawrence et al. 2007) are near completion, and are already releasing their data products or will start this release soon. In the southern hemisphere, the Hα VPHAS+ and near-infrared VVV ESO public surveys will start observations as soon as their associated instrumentation are available. The scientific exploitation of the survey data will produce an increase of several orders of magnitude of the number of Be stars known in our Galaxy. All these developments configure a scenario of an exciting and rapidly evolving field of research. In this context, it seems timely for a new major international meeting of researchers on active B stars in the 2009–2011 time frame. Although it is still in the initial discussion stage, actions in this direction have already been undertaken. Juan Fabregat & Geraldine J. Peters chairs of Working Group

References

Cameron, C., Saio, H., Kuschnig, R. et al. 2008, arXiv:0805.1720 Domiciano de Souza, A., Kervella, P., Jankov, S. et al. 2003, A&A, 407, L47 Drew, J.E., Greimel, R., Irwin, M.J. et al. 2005, MNRAS, 362, 753 Gies, D.R., Bagnuolo, W.G., Baines, E.K. et al. 2007, ApJ, 654, 527 Lawrence, A., Warren, S. J., Almaini, O. et al. 2007, MNRAS, 379, 1599 Meilland, A. et al. 2007, A&A, 464, 59 Michel, E., Baglin, A., Auvergne, M. et al. 2006, in: Fridlund, M., Baglin, A., Lochard, J. & Conroy, L. (eds.), The CoRoT Mission, ESA-SP, 1306, 39 Neiner, C., Hubert, A.M., Fr´emat,Y. et al. 2003, A&A, 409, 275 Okazaki, A. T., Owocki, S. P., & Steﬂ,ˇ S. 2007, Active OB-Stars: Laboratories for Stellar and Circumstellar Physics, ASP-CS, 361 Peters, G.J., Gies, D.R., Grundstrom, E.D., McSwain, M.V. 2008, ApJ, 686, 1280 Saio, H., Cameron, C., Kuschnig, R. et al. 2007, ApJ, 654, 544 Walker, G.A.H., Kuschnig, R., Matthews, J.M. et al. 2005a, ApJ, 623, L145 Walker, G.A.H., Kuschnig, R., Matthews, J.M. et al. 2005b, ApJ, 635, L77

2012, Be Star Newsletter, 40 − 6 2.3. Business Meeting and Scientific Session of the Working Group on Active B Stars 27th IAU General Assembly, Rio de Janeiro, Brazil August 6, 2009 Session 1 (G. Peters, Chair) Business Session 09:00 1. Activities during the past triennium, future activities, report on the status of the Be Star Newsletter (G. Peters) 2. Update on IAU Symposium 272 “Active OB stars: structure, evolution, mass loss, and critical limits” to be held in Paris from 2010 July 19–23 (C. Neiner) Scientific Session 09:30 CoRoT and the Be stars (J. Fabregat) 10:00 Watching the growth of a disk: 37 days of H-alpha spectroscopy of HD 168797 (E. Grundström) 10:15 Influence of X-ray radiation on wind structure of hot stars (J. Krtiˇcka) 10:30 Coffee Break Session 2 (J. Fabregat, Chair) 16:00 Active B stars and the new class of “gamma-ray binaries”? (V. McSwain) 16:15 Magnetism in massive stars (G. Wade) 16:45 On the incidence of magnetic fields in slowly-pulsating B, beta Cephei and B-type emission line stars (J. Silvester) 17:00 Be stars in the IPHAS and VPHAS+ galactic plane surveys (J. Fabregat) 17:10 Non-radial pulsations in the open cluster NGC 3766 (R. Roettenbacher) 17:20 Analysis of B and Be star populations of the double cluster h and chi Persei (A. Marsh) 17:30 End of Session G. J. Peters

2.4. Proposal for the Bylaws for the IAU Working Group on Active B Stars ∗ I. Nature and Goals of the Working Group The Working Group on Active B Stars (formerly known as the Working Group on Be Stars) was re-established under IAU Commission No. 29 in 1979 at the 17th IAU General Assembly in Montreal, Canada, and has been in continuous operation to the present. Its main goal is to promote and stimulate research and international collaboration in the ﬁeld of the active early-type (OB) stars. The focus of the WG was originally on the classical Be stars, but in recent years there has been an increasing contact and overlap with other research areas, particularly in closely aligned topics such as pulsating OB stars and B stars in interacting binaries. The Working Group on Active B Stars is an IAU Inter-Divisional Working Group sponsored by Divisions IV (Stars) and V (Variable Stars).

2012, Be Star Newsletter, 40 − 7 Our goal is to investigate active phenomena in B-type stars including mass loss and accretion, pulsations, rotation, magnetic fields, and binarity and determine the fundamental parameters for these objects and to promote collaboration and interaction between scientists specializing in these studies. II. Membership Membership is open to any scientist working in the field of active B stars, including amateur scientists. IAU membership is required to run for a place on the Scientific Organizing Committee (SOC) and to serve on the SOC. Members receive e-mail updates on news items published in the Be Star Newsletter, the official publication for the Working Group. One can join the Working Group by contacting the webmaster of the Be Star Newsletter. III. Newsletter and Website The Be Star Newsletter is the official publication for the Working Group. It is published irregularly with a frequency governed by the number of items submitted. News items, including announcements for meetings of interest to the Working Group and abstracts of new papers, and longer articles are submitted to the Editor-in-Chief. All articles are reviewed by anonymous referees who advise the Editor-in-Chief on the suitability for publication. All accepted articles are published on the official website for the Working Group soon after they have been accepted by the Editor-in-Chief. The website is maintained by a web editor. The technical editor is responsible for arranging for the printing and mailing of a paper copy of the Newsletter. IV. Election of the Scientific Organizing Committee for the Working Group The duties of the Scientific Organizing Committee are to decide policy issues for the Working Group and help prepare proposals for scientific meetings of interest to the Working Group. Each member of the Working Group who is also an IAU member is permitted to nominate four persons as candidates for the new SOC and send them to the Election Officer. The Election Officer selects 10 candidates with the highest number of votes. If several individuals have the same number of nominations for the last spot on the ballot, they are all accepted and the number of candidates will be higher than 10. According to the general IAU rules, only IAU members or new members pending approval at the current General Assembly can be accepted as candidates for SOC membership, and balanced regional representation should be taken into account in nomination of the candidates. The Election Officer must verify that all nominees to be listed as candidates on the ballot are willing to serve if elected. The four new SOC members are elected from the candidates by the members of the Working Group, who are members of the IAU, and may vote for up to four different persons. The four persons with the largest numbers of valid votes are elected. Their term lasts for the duration of six years, and begins at the conclusion of the IAU General Assembly in the year they are elected. A person must wait for six years, or two IAU General Assemblies, in order to run again for a position on the SOC. The four new and the four continuing SOC members determine among themselves the new Chairperson. ∗ Still under discussion with SOC and membership.

2012, Be Star Newsletter, 40 − 8 2.5. PROCEEDINGS: Business Meeting of the Working Group on Active B Stars 27th IAU General Assembly, Rio de Janeiro, Brazil August 6, 2009

PRESIDENT Geraldine J. Peters VICE-PRESIDENT Carol E. Jones, Richard D. Townsend PAST PRESIDENT Juan Fabregat MEMBERS Karen S. Bjorkman, M. Virginia McSwain, Ronald E. Mennickent, Coralie Neiner, Philippe Stee, Juan Fabregat (non-voting)

PROCEEDINGS BUSINESS SESSIONS, 6 August 2009

2.5.1. Introduction

The meeting of the Working Group on Active B Stars consisted of a business session followed by a scientiﬁc session containing nine talks. The titles of the talks and their presenters are listed below. We plan to publish a series of articles containing summaries of these talks in Issue No. 40 of the Be Star Newsletter 2. This report contains an account of the announcements made during the business session, an update on a forthcoming IAU Symposium on active B stars, a report on the status of the Be Star Newsletter, the results of the 2009 election of the SOC for the Working Group for 2009–12, a listing of the Working Group bylaws that were recently adopted, and a list of the scientiﬁc talks that we presented at the meeting.

2.5.2. Business Session

2.5.2.1. Announcements 1. A proposal to continue IAU recognition of the Working Group was submitted by G. Peters & J. Fabregat by the 2009 February 28 deadline. 2. The triennium report for the WG for 2006–09 was prepared and submitted by J. Fab- regat & G. Peters by the 2008 July deadline. It was published in 2008 December in IAU Transactions XXVIIA and in Issue No. 40 of the Be Star Newsletter. 3. A proposal to hold a meeting on active B stars in Paris in the summer of 2010 was submitted by C. Neiner by the 2008 December 1 deadline. Our proposal entitled “Active OB stars: structure, evolution, mass loss, and critical limits” was accepted as one of the eight IAU Symposia to be held in 2010. It has been designated as IAU Symposium No. 272 and will take place from July 19 –23.

2.5.2.2. IAU Symposium No. 272 C. Neiner, chair of the SOC for IAU S272 “Active OB stars: structure, evolution, mass loss, and critical limits” presented an update on the plans for the meeting. The venue for

2The oﬃcial publication for the IAU Working Group on Active B Stars.

2012, Be Star Newsletter, 40 − 9 the meeting will be Eurosites-R´epublique, 8 bis, rue de la Fontaine au Roi, 75011 Paris. An overview of the scientiﬁc program, key dates, and social events can be found on the meeting’s website http://iaus272.obspm.fr/.

2.5.2.3. Be Star Newsletter The Be Star Newsletter, which is published in hard copy at Georgia State University for the Working Group on Active B Stars, continues to be the main source of information on new discoveries, ideas, manuscripts, and meetings on active B stars. G. Peters, D. Gies, and D. McDavid continue, respectively, as Editor-in-Chief, Technical Editor, and Webmaster. Abstracts and announcements are usually posted on our website (http://www.astro.virginia.edu/∼dam3ma/benews/) within 48 hrs of being received. Articles submitted for publication have been refereed since 2000 leading to an improvement in the quality of the Newsletter. When we have accumulated about 50 pages of material we ﬁnalize an issue and print hard copies that are mostly distributed to libraries worldwide. We encourage researchers to submit material to our Community Comments section that we introduced in 2005 to allow Working Group members to voice opinions or ideas on which the community can submit rebuttal, similar to unedited discussion that is sometime published as part of meeting proceedings. During the past triennium we have published Issues Number 38 (March 2007) and 39 (June 2009). The latter contains the proceedings from the scientiﬁc session held during the meeting of the Working Group on Active B Stars at the 26th IAU General Assembly in Prague, Czech Republic.

2.5.2.4. SOC Election Results The election to replace the four retiring members of the SOC was held in 2009 July. E-mail ballots were sent to all current IAU members of the Working Group on Active B Stars. The Scientiﬁc Organizing Committee (SOC) for the 2009–12 triennium is:

Term expiring in 2012: Karen Bjorkman, Coralie Neiner, Geraldine Peters, Philippe Stee Term expiring in 2015: Carol Jones, Virginia McSwain, Ronald Mennickent, Richard Townsend Non-voting: Christopher Corbally (President of IAU Division IV: Stars), Steven D. Kawaler (President of IAU Division V: Variable Stars), Juan Fabregat (Outgoing SOC Chair)

2.5.2.5. Bylaws for the IAU Working Group on Active B Stars A key action item for the triennium 2006–09 was to establish a formal set of bylaws for the Working Group. These were ﬁnalized by the SOC prior to this businesses meeting and are presented verbatim below.

I. Nature and Goals of the Working Group The Working Group on Active B Stars (formerly known as the Working Group on Be Stars) was re-established under IAU Commission No. 29 in 1979 at the 17th IAU General Assembly in Montreal, Canada, and has been in continuous operation to the present. Its main goal is to promote and stimulate research and international collaboration in the ﬁeld of the active early-type (OB) stars. The focus of the WG was originally on the classical Be stars, but in recent years there has been an increasing contact and overlap with other research areas, particularly in closely aligned topics such as pulsating OB stars and B stars in interacting

2012, Be Star Newsletter, 40 − 10 binaries. The Working Group on Active B Stars is an IAU Inter-Divisional Working Group sponsored by Divisions IV (Stars) and V (Variable Stars). Our goal is to investigate active phenomena in B-type stars including mass loss and accretion, pulsations, rotation, magnetic fields, and binarity and determine the fundamental parameters for these objects and to promote collaboration and interaction between scientists specializing in these studies. II. Membership Membership is open to any scientist working in the field of active B stars, including amateur scientists. IAU membership is required to run for a place on the Scientific Organizing Committee (SOC) and to serve on the SOC. Members receive e-mail updates on news items published in the Be Star Newsletter, the official publication for the Working Group. One can join the Working Group by contacting the webmaster of the Be Star Newsletter. III. Newsletter and Website The Be Star Newsletter is the official publication for the Working Group. The Newslet- ter is published irregularly with a frequency governed by the number of items submitted. News items, including announcements for meetings of interest to the Working Group and abstracts of new papers, and longer articles are submitted to the Editor-in-Chief. All articles are reviewed by anonymous referees who advise the Editor-in-Chief on the suitability for publication. All accepted articles are published on the official website for the Working Group soon after they have been accepted by the Editor-in-Chief. The website is maintained by a web editor. The technical editor is responsible for arranging for the printing and mailing of a paper copy of the Newsletter. IV. Election of the Scientific Organizing Committee for the Working Group The duties of the Scientific Organizing Committee (SOC) are to establish scientific policy of the Working Group, set up mechanisms to stimulate the collaboration between its members, and help to prepare proposals for scientific meetings of interest to the Working Group. Each member of the Working Group who is also an IAU member is permitted to nominate four persons as candidates for the new SOC and send them to the Election Officer. The Election Officer selects 10 candidates with the highest number of votes. If several individuals have the same number of nominations for the last spot on the ballot, they are all accepted and the number of candidates will be higher than 10. According to the general IAU rules, only IAU members or new members pending approval at the forthcoming General Assembly can be accepted as candidates for SOC membership Geographically balanced representation should be taken into account in the nomination of the candidates. The Election Officer must verify that all nominees to be listed as candidates on the ballot are willing to serve if elected. The four new SOC members are elected from the candidates by the members of the Working Group who are members of the IAU. Each IAU member may vote for up to four different persons. The four persons with the largest numbers of valid votes are elected. In the case of a tie, a runoff election will be held. The term of an SOC member lasts for a duration of six years, and begins at the conclusion of the IAU General Assembly in the year he/she is elected. A person must wait for six years, or two IAU General Assemblies, in order to run again for a position on the SOC. The four new and the four continuing SOC members determine among themselves the new Chairperson. V. Ratification of the Bylaws The bylaws are ratified by the SOC, and may be amended as per input from the Working

2012, Be Star Newsletter, 40 − 11 Group membership. Ratiﬁcation is by a simple majority, or a yes vote by at least 5/8 SOC members. Amendments become valid at the conclusion of each IAU General Assembly.

2.5.3. Scientiﬁc program

Session 1 (G. Peters, Chair) 09:30 CoRoT and the Be stars J. Fabregat 10:00 Watching the growth of a disk: 37 days of H-alpha spectroscopy of HD 168797 E. Grundstrom 10:15 Influence of X-ray radiation on wind structure of hot stars J. Krtiˇcka 10:30 Coffee Session 2 (J. Fabregat, Chair) 16:00 Active B stars and the new class of “gamma-ray binaries”? V. McSwain 16:15 Magnetism in massive stars G. Wade 16:45 On the incidence of magnetic fields in slowly-pulsating B, β Cephei and B-type emission line stars J. Silvester 17:00 Be stars in the IPHAS and VPHAS+ galactic plane surveys J. Fabregat 17:10 Non-radial pulsations in the open cluster NGC 3766 R. Roettenbacher 17:20 Analysis of B and Be star populations of the double cluster h and χ Persei A. Marsh 12:30 Session Ends

2.5.4. Closing remarks

I would like to thank the speakers who presented a set of excellent talks and all who attended the Working Group meeting. Impressive new information on the nature of B stars and their activity is emerging that could barely be imagined three decades ago when this Working Group was re-established at the XVII IAU General Assembly in Montreal, Quebec. We heartedly thank outgoing SOC chair Juan Fabregat, for his skillful leadership and assistance in preparing the various reports and other documents that were submitted to the IAU General Secretary. We are looking forward to seeing you again in 2012 at the meeting of the Working Group on Active B Stars at the 28th IAU General Assembly in Beijing. Geraldine J. Peters Chair of the Working Group, 2009–12

2012, Be Star Newsletter, 40 − 12 2.6. Greetings from the Chair of the Working Group Hello to the Active B Star Community, I am honored to have the opportunity to serve as the Chair of the Working Group on Active B Stars for the next triennium and thank the SOC for their support. First of all I would like to heartedly thank Juan Fabregat for his service as Co-Chair of the Working Group during the last triennium. His help in responding to the requests from the General Secretary and insuring that all reports were submitted on time was especially valuable. I am pleased to introduce the newly-elected SOC members Carol Jones, Ginny McSwain, Ronald Mennickent, and Rich Townsend, whose terms will extend until the end of the 29th IAU General Assembly in Hawaii in August of 2015. They join Karen Bjorkman, Coralie Neiner, Philippe Stee, and myself who will serve until the end of the 28th GA in Beijing in 2012 August. Let us all extend our thanks to the retiring SOC members Juan Fabregat, Doug Gies, Huib Henrichs, and David McDavid for their service on the SOC from 2003–09. For the first time in the history of the Working Group we have established the post of Vice Chair. The duties of the Vice Chair will include assisting the Chair with the preparation of the various reports that are requested by the General Secretary. I am happy to report that Carol Jones and Rich Townsend have agreed to serve as Vice Chairs for 2009–12. Our meeting of the WGABS at the recent IAU GA in Rio de Janeiro was a resounding success with many excellent talks, and I thank all of the speakers for their efforts. A series of short papers that are based on these talks will soon appear in the Newsletter. Stay tuned as the papers come in! I am pleased to report that the SOC passed a set of bylaws for the WG just prior to our meeting in Rio. These bylaws are posted on the Newsletter’s website. Our current procedure is to amend/modify the bylaws every three years prior to the meeting of the WG at the IAU GA. All Working Group members, including the SOC, are welcome to propose changes to the bylaws. If there is an urgent need to change the bylaws prior to the next GA the SOC will act upon it. Please read over the current bylaws and let us know anything that should be changed or clarified. The next major event for the WGABS is IAU-S272 on “Active OB stars: structure, evolution, mass loss, and critical limits” in Paris, France from 2010 July 19 –23. Plans are well underway. Please check the website http://iaus272.obspm.fr/ and the Newsletter for updates. Looking forward to seeing all of you in Paris. One of my priorities for the forthcoming triennium is to expand interest in our research on active B stars and find more common ground with researchers who work on O and A stars, pre-main sequence stars, interacting binaries with an early-type primaries, and fundamental parameters including elemental abundances in hot stars. I would like to see more abstracts and articles on the latter objects in the Be Star Newsletter. If you have ideas for action items for our agenda, we encourage your input. Please write to anyone on the SOC at any time. I am indeed looking forward to a lively and productive triennium on active B star research. Gerrie Peters, Chair of the Working group on Active B Stars (2009–12)

2.7. Thoughts from the Outgoing Chair of the Working Group Dear Colleagues, At the last IAU General Assembly in Rio de Janeiro my membership on the SOC and my mandate as Co-Chair of the Working Group came to an end. First of all I would like to thank

2012, Be Star Newsletter, 40 − 13 all of you who contribute to make these tasks a very enriching and pleasant experience, both in the professional and personal sides. Particular thanks to the members of the SOC for their confidence and support, and to Gerrie Peters, Doug Gies and David McDavid for their continued effort in maintaining the Be Stars Newsletter as an efficient and reliable source of information about what is going on in relation with the active B stars research. And a very special thank to Gerrie Peters for her service as Co-Chair during the last triennium, and for her generosity in assuming the Chair for the next period 2010–2012. Her expertise and enthusiasm made my work an easy and pleasant task. I am sure our Working Group remains in the best hands. The field of Be star research has been very active during the last triennium, and we can expect this activity to increase. The recent development of powerful instrumentation, both ground-based and in space, has led to significant progress in our understanding of active B stars physics. High precision photometry from spacecraft (MOST, CoRoT, Kepler) and its analysis with the techniques of asteroseismology is providing important insights on the internal structure of Be stars and their rotation. The advent of the VLTI interferometer and the CHARA array has allowed the spatial resolution of several Be star photospheres and disks. The new generation of high-resolution spectropolarimeters (Narval, Espadons) provides clues about magnetic fields and the confinement of the circumstellar environment. Large on-going and future galactic plane surveys (IPHAS, VPHAS+, INTEGRAL) are uncovering new populations of different classes of active B stars, with a great potential for studies of galactic structure. All these and many other hot topics and new developments in the field of the active B star research will be presented at the upcoming IAU Symposium 272 “Active OB stars: structure, evolution, mass loss and critical limits”, to be held in Paris in July 19–23, 2010. Symposium 272 constitutes the next major gathering of the Be star community worldwide, following the successful meetings held in Alicante (1999) and Sapporo (2005). I look forward to seeing most of you in Paris next July. Juan Fabregat, Co-Chair of the Working group on Active B Stars (2006-09)

2.8. Call for Presentations at the IAU GA in Beijing

I am pleased to announce that the Working Group on Active B Stars has been granted two sessions at the forthcoming IAU General Assembly in Beijing, China to hold a combined business/scientiﬁc meeting. The sessions will be held from 14:00–15:30 and 16:00–18:00 on Wednesday, August 22 in Room 403 at the China National Convention Center. If you are planning on attending the General Assembly and would like to present a talk at the WG meeting please send me a title and an estimate of how much time you might need. We usually schedule talks for 15 or 30 min. The deadline for early registration for the IAU GA is March 17. Looking forward to seeing you in Beijing. Gerrie Peters Chair, WGABS 2009–12 [email protected] or [email protected]

2012, Be Star Newsletter, 40 − 14 2.9. WGABS Meeting at the IAU GA in Beijing As announced earlier the Working Group on Active B Stars has been granted two sessions at the forthcoming IAU General Assembly in Beijing, China to hold a combined business/scientiﬁc meeting. The sessions will be held from 14:00–15:30 and 16:00–18:00 on Wednesday, August 22 in Room 403 at the China National Convention Center. We are now ﬁnalizing the program for the meeting. If you are planning on attending the General Assembly and would like to present a talk at the WG meeting please send me a title ASAP and an estimate of how much time you might need. We usually schedule talks for 15 or 30 min. Looking forward to seeing you in Beijing. Gerrie Peters Chair, WGABS 2009–12 [email protected] or [email protected]

2.10. SOC Election 2012: IAU WORKING GROUP on ACTIVE B STARS

CHAIR Geraldine J. Peters VICE-CHAIRS Carol E. Jones, Richard D. Townsend PAST CHAIR Juan Fabregat BOARD Karen S. Bjorkman, M. Virginia McSwain, Ronald E. Mennickent, Coralie Neiner, Philippe Stee

Dear Members of the IAU Working Group on Active B Stars, It is again time to elect new members of the SOC of the Working Group on Active B Stars. As in the recent past, we will hold the election by e-mail ballot and announce the results during the business meeting of the WGABS at the next IAU General Assembly, this time in Beijing. There will be four vacancies on the SOC left by members whose terms expire in 2012. Current members are: Terms expiring in 2012: Karen Bjorkman Coralie Neiner Geraldine Peters Philippe Stee Terms expiring in 2015: Carol Jones Virginia McSwain Ronald Mennickent Richard Townsend Non-voting: President of IAU Division IV: Stars President of IAU Division V: Variable Stars Outgoing SOC Chair: Juan Fabregat If you would like to put forth a nomination, please send the names of no more than four

2012, Be Star Newsletter, 40 − 15 persons to the Election Officer, David McDavid ([email protected]), no later than Sunday, July 15. After that date we will prepare an e-ballot. Please keep in mind that in order to nominate and vote, you must be a current member of the IAU or a new member pending approval at the forthcoming GA (see the Bylaws ratified in the WG business session of 6 August 2009). It would also be helpful if you would confirm that each nominee agrees to stand for election and serve on the SOC if elected. In the past we have practiced the non-firm rule that a person must wait at least two GAs (6 years) before running again for a place on the SOC. Looking forward to hearing from you, Gerrie Peters, Chair, WGABS 2009–12 David McDavid, Election Officer

2.11. Division IV-V / Working Group Active B-Type Stars: Triennial Report 2009-2012

TRIENNIAL REPORT 2009-2012

2.11.1. Introduction

The Working Group on Active B Stars (WGABS) was re-established under IAU Commission No. 29 at the IAU General Assembly in Montreal, Quebec, Canada in 1979. Its main goal is to promote and stimulate research and international collaboration in the ﬁeld of active B stars. Originally known as the Working Group on Be Stars, its name was changed at the 22nd IAU General Assembly in The Hague, Netherlands in 1994 when the research interests of the group were broadened to include activity in all B stars, especially pulsating OB stars, interacting binaries, stellar winds, and magnetic ﬁelds.

2.11.2. Developments within the past triennium

The Be Star Newsletter (http://www.astro.virginia.edu/∼dam3ma/benews/) has continued to be the main source of information on new discoveries, ideas, manuscripts, and meetings on active B stars. G. Peters, D. Gies, and D. McDavid continue, respectively, as Editor-in-Chief, Technical Editor, and Webmaster. News items and abstracts are published online soon after they are accepted. Since 2000 all contributions have been refereed. When suﬃcient material is accumulated an issue is formed and a paper version is distributed. Issue No. 39 was published in June 2009, and contains 20 research notes and advertisements of interest to the active B star community and 32 abstracts of papers. The current working issue No. 40 contains 24 research notes and 34 abstracts received by 20 October 2011.

2012, Be Star Newsletter, 40 − 16 The proceedings of the last major meeting on active B stars, “Active OB-Stars: Laboratories for Stellar and Circumstellar Physics”, held in Sapporo, Japan, were published in March 2007 (Okazaki, Owocki & Steflˇ 2007). IAUS-272 (Active OB Stars: Structure, Evolution, Mass-Loss, and Critical Limits) was held in Paris, France from 19–23 July 2010. The key topics included the internal structure of active OB stars (pulsations, rotation, magnetism, transport processes), evolution of OB stars (formation, binaries, late evolutionary stages including magnetars and GRBs), the circumstellar environment (disks, magnetospheres, Be phenomenon, and winds), OB stars as extreme condition test beds (critical rotation, mass loss, radiation fields), normal OB stars for calibration purposes (fundamental parameters, astronomical quantities), and populations of OB stars (studies, tracers of galactic structure, cosmic history). The symposium was supported by IAU Divisions IV (Stars) & V (Variable Stars), Commissions 27 (Vari- able Stars), 36 (Theory of Stellar Atmospheres), and 42 (Close Binary Stars), and Working Groups on Active B Stars, Ap and Related Stars, and Massive Stars. There were over 150 participants. The Proceedings, edited by Coralie Neiner, Gregg Wade, Georges Meynet, and Geraldine Peters, were published in July 2011. High resolution interferometry in the optical and the infrared is continuing to be a valuable probe for circumstellar material surrounding massive stars especially for the disk-like structures that surround Be stars. Improvements in this observational technology now allows angular scales below 1 milli-arcsecond to be reached and in turn has resulted in advances in our understanding of these disk structures (Tycner, C. 2011). For example, interferometry has been used to model individual stars (Stefl,ˇ S. et al. 2011; Schaefer, G. H. et al. 2011; Delaa et al. 2011), compute disk sizes in various wavelength regimes (Millan-Gabet, R. et al. 2010; Meilland, A. et al. 2008), infer the disk density structure (Tycner, C. et al. 2008), find binary systems (Koubský,P. et al. 2010; Meilland, A. et al. 2008), and estimate disk mass (Kraus, S. et al. 2011). New data combined with other observables has led to successful dynamic models that follow disk structure over time to be developed and tested (c.f. Carciofi et al. 2009). Key to continuing progress will be further development of theoretical models tightly constrained by observations. Interferometric imaging still suffers from sparse (u, v) plane coverage, and theoretical images play a critical role in interpreting the observations. Several groups have developed this modeling capacity (c.f. Carciofi et al. 2009; Kervella, P. et al. 2009; Jones, C. E. et al. 2008; Schaefer, G. H. et al. 2011) and further refinements of these models are expected. Theoreticians and observers from this active area of research will meet in Foz do Igua¸cu,Brazil in February 2012 at a European Southern Observatory workshop entitled, Circumstellar Dynamics at High Resolution. The origin of magnetic fields in B stars and their role in generating short- term activity and controlling the evolution is currently a topic of widespread interest. The MiMeS (Magnetism in Massive Stars) Project (Wade, G. A. et al. 2011) is an international collaborative effort that has been awarded 1230 hours of observing time on the Canada-France-Hawaii Telescope and the Telescope Bernard Lyot from 2008–12 to obtain high resolution spectropolarimetry with the ESPaDOnS and Narval instruments. Data on 25 targeted stars and ∼200 survey stars are being modeled by contemporary codes (e.g. Townsend, R. H. D. et al. 2007; ud- Doula, A. et al. 2008). The Kepler, CoRoT, and MOST spacecraft continue to produce high- quality photometry of active B stars (especially the β Cep, Be, and SPB stars) over long baselines (Balona et al. 2011; De Cat et al. 2011; Gutiérrez-Soto,J. et al. 2011). Along with spectroscopic information these observations reveal a rich set of pulsational frequencies and modes from which constraints can be placed on the internal rotation, metallicity, and the nature of

2012, Be Star Newsletter, 40 − 17 sub-photospheric convection. The Fermi Gamma-ray Space Telescope is providing a wealth of data on a rare group of Be/X-ray binaries that exhibit very high energy emission in the MeV–TeV range. Ongoing studies are investigating their stellar/compact companion interactions, identify the mechanism for particle acceleration, and determine the nature of the compact companions (e.g. Aragona et al. 2009; McSwain, M. V. et al. 2010). Large surveys are yielding information on the nature of entire classes of active B stars, and the extent of the variability in individual objects. The Spitzer SAGE survey of the Magellanic Clouds (Bonanos et al. 2011) that includes ∼5000 OB stars from which Be stars can be clearly identified reveals a higher percentage of Be stars in the SMC and frequent transitions from a Be- phase to a non-emission state. The VLT-FLAMES surveys of OB stars in the Galaxy and Magellanic Clouds are providing fundamental parameters for thousands of OB stars (Evans, C. J. et al. 2005, 2006; Lennon, D. J. et al. 2011). Stellar models and evolutionary tracks for B stars continue to become more representative of actual stars with the inclusion of rotation, magnetic fields, and lower metallicities (cf. Zahn, J.-P. 2011; Ekstrom, S. et al. 2011a,b, 2008) in their computation. Evolutionary models for rotating stars predict an enhancement in the nitrogen abundance due to merid- ional circulation and turbulent diffusion of CNO-processed material from the stellar core to the photosphere. The effect becomes more prominent at very high rotational velocities. Several investigations have failed to confirm an elevated N abundance in Be stars in general (Brott et al. 2011; Dunstall et al. 2011; Peters, G. J. 2011) and thus do not offer support for the presence of critical rotation in these objects. Substantial progress was made on the computation of evolutionary models for Algol binaries with B-type primaries (Van Rens- bergen, W. et al. 2011) taking into account mass loss from the system from spin-up of the mass gainer and the creation of an accretion hot spot due to the impacting gas stream. Computations of 561 models (Van Rensbergen, W. et al. 2008) are available through the CDS.

2.11.3. Closing remarks

The WGABS has seen significant advances in our understanding of the activity and the evolution of B-type stars during the past triennium. Large collaborations have produced substantial databases from ground-based telescopes and spacecraft that reveal information on disk geometry and structure, the nature of magnetic fields, pulsation characteristics, and fundamental stellar parameters. Evolutionary models for single stars and Algol binaries are increasingly representing actual stars, though more attention must be given to predicting the N abundances and distribution of mass ratios for the binaries. Mass-loss, rotation, and accretion in hot stars are important processes that still lack sufficient understanding. They affect the evolution of massive stars and, in turn, these stars govern the evolution of their parent galaxies. Circumstellar disks and winds offer unique laboratories for studying these key phenomena. Juan Fabregat & Geraldine J. Peters chairs of Working Group

2012, Be Star Newsletter, 40 − 18 References

Aragona, C., McSwain, M. V., & De Becker, M. 2010, ApJ, 724, 306 Balona, L. A., & 35 co-authors 2011, MNRAS, 413, 2403 Bonanos, A. Z., & 10 co-authors 2011, in: C. Neiner, G. Wade, G. Meynet, G. Peters (eds.), Active OB Stars: Structure, Evolution, Mass-Loss, and Critical Limits, Proc. IAU Symposium No. 272, Paris, France, 19–23 July 2010 (Cambridge: University Press), p. 254 Brott, I., Evans, C. J., Hunter, & 9 co-authors 2011, A&A, 530, A16 Carciofi, A. C., Okazaki, A. T., Le Bouquin, J.-B., & 5 co-authors 2009, A&A, 504, 915 De Cat, P., Uytterhoeven, K., Gutiérrez-Soto,J., Degroote, P., & Simón-Diáz,S. 2011, in: C. Neiner, G. Wade, G. Meynet, G. Peters (eds.), Active OB Stars: Structure, Evolution, Mass- Loss, and Critical Limits, Proc. IAU Symposium No. 272, Paris, France, 19–23 July 2010 (Cambridge: University Press), p. 433 Delaa, O., Stee, Ph., Meilland, A., & 18 co-authors 2011, A&A, 529, 87 Dunstall, P. R., Brott, I., Dufton, P. L., Lennon, D. J., Evans, C. J., Smartt, S. J., & Hunter, I. 2011, astro-ph, arXiv:1109.6661 Ekstrom, S., Meynet, G., Maeder, A., & Barblan, F. 2008, A&A, 478, 467 Ekstrom, S., Georgy, C., Meynet, G., Maeder, A., & Granada, A. 2011a, in: C. Neiner, G. Wade, G. Meynet, G. Peters (eds.), Active OB Stars: Structure, Evolution, Mass-Loss, and Critical Limits, Proc. IAU Symposium No. 272, Paris, France, 19–23 July 2010 (Cambridge: Univer- sity Press), p. 62 Ekstrom, S., & 10 co-authors 2011b, astro-ph, arXiv:1110.5049, http://obswww.unige.ch/Recherche/evol/-Database- Evans, C. J., & 25 co-authors 2005, A&A, 437, 467 Evans, C. J., Lennon, D. J., Smartt, S. J., & Trundle, C. 2006, A&A, 456, 623 Gies, D. R., Touhami, Y. N., & Schaefer, G. H. 2011, in: C. Neiner, G. Wade, G. Meynet, G. Peters (eds.), Active OB Stars: Structure, Evolution, Mass-Loss, and Critical Limits, Proc. IAU Symposium No. 272, Paris, France, 19–23 July 2010 (Cambridge: University Press), p. 390 Gutiérrez-Soto,J., & 6 co-authors 2011, in: C. Neiner, G. Wade, G. Meynet, G. Peters (eds.), Active OB Stars: Structure, Evolution, Mass-Loss, and Critical Limits, Proc. IAU Symposium No. 272, Paris, France, 19–23 July 2010 (Cambridge: University Press), p. 451 Jones, C. E., Tycner, C., Sigut, T. A. A., Benson, J. A., & Hutter, D. J. 2008, ApJ, 687, 598 Kervella, P., Domiciano de Souza, A., Kanaan, S., Meilland, A., Spang, A., & Stee, Ph. 2009, A&A, 493, 53 Koubský,P., Hummel, C. A., Harmanec, P., Tycner, C., & 7 co-authors 2010, A&A, 517, 24 Kraus, S., Monnier, J. D., Che, X., Schaefer, G. H., & 10 co-authors 2011, astro-ph, arXiv:1109.3447 Lennon, D. J., & 30 co-authors 2011, in: C. Neiner, G. Wade, G. Meynet, G. Peters (eds.), Active OB Stars: Structure, Evolution, Mass-Loss, and Critical Limits, Proc. IAU Symposium No. 272, Paris, France, 19–23 July 2010 (Cambridge: University Press), p. 296 McSwain, M. V., Grundstrom, E. D., Gies, D. R., & Ray, P. S. 2010, ApJ, 724, 379 Meilland, A., Millour, F., Stee, Ph., & 5 co-authors 2008, A&A, 488, 67 Millan-Gabet, R., Monnier, J. D., Touhami, Y., 6 co-authors, & the CHARA group 2010, ApJ, 723, 544 Okazaki, A. T., Owocki, S. P., & Stefl,ˇ S. 2007, Active OB-Stars: Laboratories for Stellar and Circumstellar Physics, ASP-CS, 361 Peters, G. J. 2011, in: C. Neiner, G. Wade, G. Meynet, G. Peters (eds.), Active OB Stars: Structure, Evolution, Mass-Loss, and Critical Limits, Proc. IAU Symposium No. 272, Paris, France, 19– 23 July 2010 (Cambridge: University Press), p. 101 Schaefer, G. H., & 5 co-authors 2011, in: C. Neiner, G. Wade, G. Meynet, G. Peters (eds.), Active OB Stars: Structure, Evolution, Mass-Loss, and Critical Limits, Proc. IAU Symposium No. 272, Paris, France, 19–23 July 2010 (Cambridge: University Press), p. 424 Stefl,ˇ S., Carciofi, A. C., & 7 co-authors 2011, in: C. Neiner, G. Wade, G. Meynet, G. Peters (eds.), Active OB Stars: Structure, Evolution, Mass-Loss, and Critical Limits, Proc. IAU Symposium No. 272, Paris, France, 19–23 July 2010 (Cambridge: University Press), p. 430 Townsend, R. H. D., Owocki, S. P., & Ud-Doula, A. 2007, MNRAS, 382, 139 Tycner, C., Jones, C. E., Sigut, T. A. A., & 4 co-authors 2008, ApJ, 689, 461

2012, Be Star Newsletter, 40 − 19 Tycner, C. 2011, in: C. Neiner, G. Wade, G. Meynet, G. Peters (eds.), Active OB Stars: Structure, Evolution, Mass-Loss, and Critical Limits, Proc. IAU Symposium No. 272, Paris, France, 19–23 July 2010 (Cambridge: University Press), p. 337 ud-Doula, A., Owocki, S. P., & Townsend, R. H. D. 2008, MNRAS, 385, 97 Van Rensbergen, W., De Greve, J. P., De Loore, C., & Mennekens, N. 2008, A&A, 487, 1129 (see also CDS, catalog: cats/J/A+A/487/1129) Van Rensbergen, W., De Greve, J. P., Mennekens, N., Jansen, K., & De Loore, C. 2011, A&A, 487, 1129 Wade, G. A., & 19 co-authors(2011), in: C. Neiner, G. Wade, G. Meynet, G. Peters (eds.), Active OB Stars: Structure, Evolution, Mass-Loss, and Critical Limits, Proc. IAU Symposium No. 272, Paris, France, 19–23 July 2010 (Cambridge: University Press), p. 118 Zahn, J.-P. 2011, in: C. Neiner, G. Wade, G. Meynet, G. Peters (eds.), Active OB Stars: Structure, Evolution, Mass-Loss, and Critical Limits, Proc. IAU Symposium No. 272, Paris, France, 19–23 July 2010 (Cambridge: University Press), p. 14

2.12. Updated Working Group Bylaws Approved by SOC Gerrie Peters, 2009–2012 Chair, reports that the 2009–2012 SOC has approved the following updated bylaws for the IAU Working Group on Active B Stars. I. Nature and Goals of the Working Group The Working Group on Active B Stars (formerly known as the Working Group on Be Stars) was re-established under IAU Commission No. 29 in 1979 at the 17th IAU General Assembly in Montreal, Canada, and has been in continuous operation to the present. Its main goal is to promote and stimulate research and international collaboration in the field of the active early-type (OB) stars. The focus of the WG was originally on the classical Be stars, but in recent years there has been an increasing contact and overlap with other research areas, particularly in closely aligned topics such as pulsating OB stars and B stars in interacting binaries. The Working Group on Active B Stars is an IAU Inter-Divisional Working Group sponsored by Divisions IV (Stars) and V (Variable Stars). Our goal is to investigate active phenomena in B-type stars including mass loss and accretion, pulsations, rotation, magnetic fields, and binarity and determine the fundamental parameters for these objects and to promote collaboration and interaction between scientists specializing in these studies. II. Membership Membership is open to any scientist working in the field of active B stars, including amateur scientists. IAU membership is required to run for a place on the Scientific Organizing Committee (SOC) and to serve on the SOC. Members receive e-mail updates on news items published in the Be Star Newsletter, the official publication for the Working Group. One can join the Working Group by contacting the webmaster of the Be Star Newsletter. III. Newsletter and Website The Be Star Newsletter is the official publication for the Working Group. The Newslet- ter is published irregularly with a frequency governed by the number of items submitted. News items, including announcements for meetings of interest to the Working Group and abstracts of new papers, and longer articles are submitted to the Editor-in-Chief. All articles are reviewed by anonymous referees who advise the Editor-in-Chief on the suitability for publication. All accepted articles are published on the official website for the Working Group soon after they have been accepted by the Editor-in-Chief. The website is maintained by a web editor. The technical editor is responsible for arranging for the printing

2012, Be Star Newsletter, 40 − 20 and mailing of a paper copy of the Newsletter. IV. Election of the Scientific Organizing Committee for the Working Group The Scientific Organizing Committee (SOC) of the WGABS is composed of 8 members, who are elected by the membership, and non-voting members who include the past Chair of the committee, the President of Division IV, the President of Division V, and the Editor- in-Chief of the Be Star Newsletter. The duties of the Scientific Organizing Committee (SOC) are to establish scientific policy of the Working Group, set up mechanisms to stimulate the collaboration between its members, respond to requests from the IAU General Secretary, and help to prepare proposals for scientific meetings of interest to the Working Group. Each member of the Working Group who is also an IAU member is permitted to nominate four persons as candidates for the new SOC and send them to the Election Officer. The Election Officer selects 10 candidates with the highest number of votes. If several individuals have the same number of nominations for the last spot on the ballot, they are all accepted and the number of candidates will be higher than 10. According to the general IAU rules, only IAU members or new members pending approval at the forthcoming General Assembly can be accepted as candidates for SOC membership. Geographically balanced representation should be taken into account in the nomination of the candidates. The Election Officer must verify that all nominees to be listed as candidates on the ballot are willing to serve if elected. The four new SOC members are elected from the candidates by the members of the Working Group who are members of the IAU. Each IAU member may vote for up to four different persons. The four persons with the largest numbers of valid votes are elected. In the case of a tie, a runoff election will be held. The term of an SOC member lasts for a duration of six years, and begins at the conclusion of the IAU General Assembly in the year he/she is elected. A person must wait for six years, or two IAU General Assemblies, in order to run again for a position on the SOC. The four new and the four continuing SOC members determine among themselves the new Chair and Vice Chair. The outgoing Chair presides over the election of the new Chair and Vice Chair but does not vote. V. Ratification of the Bylaws The bylaws are ratified by the SOC, and may be amended as per input from the Working Group membership. Ratification is by a simple majority, or a yes vote by at least 5/8 SOC members. Amendments become valid at the conclusion of each IAU General Assembly. David McDavid Webmaster, The Be Star Newsletter

2012, Be Star Newsletter, 40 − 21 3. SCIENTIFIC PROGRAM, WORKING GROUP ON ACTIVE B STARS, IAU 27TH GENERAL ASSEMBLY

3.1. Influence of X-ray radiation on wind structure of hot stars Jiˇr´ıKrtiˇcka1 and Jiˇr´ıKubát2 1Ustav´ teoretickéfyziky a astrofyziky, Masarykova univerzita, CZ-611 37 Brno, Czech Republic email: [email protected] 2Astronomickýústav AV CR,ˇ Friˇcova 298, CZ-251 65 Ondˇrejov, Czech Republic email: [email protected] Received: 2009 October 01; Accepted: 2009 October 03.

We study influence of wind X-ray emission on wind structure of selected hot stars. To this end we include additional artificial source of X-rays (assumed to originate in wind shocks) into our NLTE wind code. We show that the influence of shock X-ray emission on wind mass-loss rate is relatively small. Wind terminal velocity may be slightly influenced by presence of strong X-ray sources, especially for stars cooler than Teff < 35 000 K. Inclusion of X-rays leads to better agreement of the model ionization structure with observations. However, we do not find any significant influence of X-rays on P V ionization fraction implying that presence of X-rays cannot explain the P V problem. We study implications of modified ionization equilibrium due to shock emission on the line transfer in the X-ray region. We conclude that X-ray line profiles of helium-like ions may be affected by line absorption within the cool wind. We show that the dependence of the shock cooling time on wind density could be important −7 for explanation of observed Lx/L = 10 relation. Stars with optically thin winds exhibiting the ‘weak wind problem’ display enhanced X-ray emission. The shock cooling length in their winds could be larger than hydrodynamical length scale. We propose that this effect can explain the ‘weak wind problem’. References Krtiˇcka, J. & Kubát,J. 2009, MNRAS, 394, 2065

3.2. Active B stars and the new class of “gamma-ray binaries”? M. Virginia McSwain Lehigh University, Department of Physics, 16 Memorial Drive E, Bethlehem, PA, USA email: [email protected] Received: 2009 October 23; Accepted: 2009 October 25.

3.2.1. Introduction The recent launch of the Fermi Gamma-ray Space Telescope heralds a new era to understand astrophysical sources of very high energy γ-rays. A key group are high mass X-ray binaries (HMXBs) that exhibit very high energy emission in the MeV-TeV range (“γ-ray binaries”). In fact, only ﬁve HMXBs are known TeV sources: LS I +61 303, LS 5039, PSR B1259−63, HESS J0632+057, and Cygnus X-1. These sources present a unique opportunity to study particle acceleration in nearby, Galactic sources. Three of the ﬁve γ-ray binaries are also Be/X-ray systems, so they present an important new class of objects of interest to the IAU

2012, Be Star Newsletter, 40 − 22 Working Group on Active B Stars. Here I present results from recent optical spectra of two such systems. LS I +61 303 is a Be/X-ray binary with spectral type B0 Ve, a 26.5 day orbital period, and highly eccentric orbit (Aragona et al. 2009). While the system has a relatively low X-ray luminosity for a HMXB, LS I +61 303 is the 15th brightest γ-ray source included in the Fermi Bright Source Catalogue (Abdo et al. 2009a). The Be disk interacts with the unknown compact companion, producing orbital phase modulated emission across the electromagnetic spectrum: TeV (Albert et al. 2006), GeV (Abdo et al. 2009b), X-ray (Paredes et al. 1997; Leahy 2001), optical Hα (Grundstrom et al. 2007), and radio (Gregory & Taylor 1978; Taylor & Gregory 1982). HESS J0632+057 is the latest proposed member of the class of γ-ray binaries, discovered as an unresolved TeV source in the HESS observations of the Monoceros Loop Supernova Remnant (Aharonian et al. 2006). An XMM-Newton investigation of the region identiﬁed a bright X-ray source within the HESS J0632+057 error box. The X-ray source position corresponds closely to the bright Be star HD 259440, which has been proposed to be the optical counterpart (Hinton et al. 2009). HD 259440 is classiﬁed as a B0pe spectral type, but not much else is known about the optical star. The binary orbital period is presently unknown, and no detailed study of the Be circumstellar disk or the star has been published. Based on its similar high energy properties, HESS J0632+057/HD 259440 has been proposed to be similar to LS I +61 303.

3.2.2. Results and Further Work During 2008 October–November, we performed 35 consecutive nights of observations of both LS I +61 303 and HD 259440 at the KPNO CoudéFeed telescope. The details of these observations are presented in Aragona et al. (2009). Our data led to an improved orbital solution for LS I +61 303, and we also discovered a possible optical flare from that source. A time series of our Hα spectra and the corresponding grayscale plot are shown in Fig. 1, left. A high velocity extension of the Hα emission profile can be seen near orbital phase φ(TG) ∼ 0.6 − 0.7. We are planning further observations during Fall 2009 to confirm the nature of that unusual emission. While we did not detect radial velocity variations of HD 259440, the Hα emission spectrum of that source revealed interesting line profile variations. After subtracting the mean emission profile from each spectrum, the difference spectra revealed a characteristic period of ∼ 60 days due to a possible spiral density wave in the circumstellar disk. These difference spectra and the corresponding grayscale plot are shown in Fig. 1, right. During the same observing run, we also obtained blue optical spectra of HD 259440 for the first investigation of its physical parameters. Measurements of its projected rotational velocity, V sin i, stellar effective temperature, Teff , and surface gravity, log g are in progress. The blue spectra are challenging to work with due to significant disk emission in many lines. Our mean blue spectrum of HD 259440 is shown in Figure 2.

2012, Be Star Newsletter, 40 − 23 4750 4750

4760 4760

4770 4770

4780 4780 HJD - 2,450,000 HJD - 2,450,000

4790 4790

0.0 0.0

0.5 0.5 Arbitrary Phase

Orbital Phase (TG) 1.0 1.0 -600 -400 -200 0 200 400 600 -400 -200 0 200 400 -1 -1 VELOCITY (km s ) VELOCITY (km s )

Figure 1. Left: The upper panel shows the Hα line profile of LS I +61 303 over our 35 nights of observation, sorted by HJD and smoothed for clarity, and the lower plot shows a gray-scale image of the same line. Note that the lower plot of the gray-scale spectra are not folded by orbital phase but are placed in the same chronological order as the upper plot, with the orbital phases indicated. The orbital phase, φTG, of LS I +61 303 is defined to be zero at HJD 2,443,366.775 (Taylor & Gregory 1982). Right: The upper panel shows the Hα difference spectra of HD 259440, illustrating variations in the circumstellar disk structure with a ∼ 60 d period. The bottom panel shows a grayscale plot of the same difference spectra. Since no period is currently known, the “Arbitrary Phase” goes from 0 at the start of the observing run to 1.0 at the end of the run.

Figure 2. The mean blue optical spectrum of HD 259440, with several prominent spectral lines identiﬁed.

2012, Be Star Newsletter, 40 − 24 References

Abdo, A. A., et al. 2009a, ApJS, 183, 46 Abdo, A. A., et al. 2009b, ApJL, 701, 123 Aharonian, F., et al. 2006, ApJ, 636, 777 Albert, J., et al. 2006, Science, 312, 1771 Aragona, C., McSwain, M. V., Grundstrom, E. D., Marsh, A. N., Roettenbacher, R. M., Hessler, K. M., Boyajian, T. S., & Ray, P. S. 2009, ApJ, 698, 514 Gregory, P. C., & Taylor, A. R. 1978, Nature, 272, 704 Grundstrom, E. D., et al. 2007, ApJ, 656, 437 Hinton, J. A., et al. 2009, ApJL, 690, L101 Leahy, D. A. 2001, A&A, 380, 516 Paredes, J. M., Mart´ı,J., Peracaula, M., & Rib´o,M. 1997, A&A, 320, L25 Taylor, A. R., & Gregory, P. C. 1982, ApJ, 255, 210

3.3. Non-radial pulsations in the open cluster NGC 3766 Rachael M. Roettenbacher, Ernest C. Amouzou, and M. Virginia McSwain Lehigh University, Department of Physics, 16 Memorial Drive E, Bethlehem, PA, USA email: [email protected], [email protected], [email protected] Received: 2009 October 26; Accepted: 2010 February 5.

3.3.1. Abstract Non-radial pulsations (NRPs) are a proposed mechanism for the formation of mass loss disks around Be stars and are important tools to study the internal structure of stars. NGC 3766 has an unusually large fraction of transient Be stars, so it is an excellent location to study the formation mechanism of Be star disks. High resolution spectroscopy can reveal line proﬁle variations from NRPs, allowing measurements of both the degree, l, and azimuthal order, m. However, spectroscopic studies require large amounts of time with large telescopes to achieve the necessary high S/N and time domain coverage. On the other hand, multi-color photometry can be performed more easily with small telescopes to measure l only. Here, we present representative light curves of Be stars and non-emitting B stars in NGC 3766 from the CTIO 0.9m telescope in an eﬀort to study NRPs in this cluster.

3.3.2. Introduction Be stars are a class of non-supergiant B-type stars with Balmer and other line emission features due to an equatorial mass loss disk. The disk is likely the result of a combination of the star’s rapid rotation (thought to be near the critical limit) and non-radial pulsations (NRPs; Porter & Rivinius 2003). NRPs are spherical harmonic waves traversing the surface of a star. These pulsations can be found in multiple frequencies on the surface simultaneously (Rivinius, Baade, & Steflˇ 2003). There are two primary classes of NRP modes: g- and p-modes. g-modes are described by a low frequency pulsation that has gravity as its restoring force. The dominant oscillation in this mode is transverse across the surface. p-modes are dominated by high frequency, radial oscillations with a pressure restoring force (De Ridder 2001). These modes in main- sequence, pulsating B stars are driven by the κ mechanism (Gutiérrez-Sotoet al. 2007). Affected primarily by the horizontal motion of low-order g-modes, temperature and flux gradients are established between the dimmer, cooler material in the troughs of the pul-

2012, Be Star Newsletter, 40 − 25 sations and the brighter, warmer material on the peaks, which is contrary to the intuitive high-order modes with cooler peaks and warmer troughs. The flux variations over the stellar surface are then observed as either ripples within photospheric absorption line profiles or as periodic variations in magnitude. A large, high-resolution spectroscopic study would reveal both the degree, l, and the azimuthal order, m, but such studies are challenging due to the need for large amounts of time on a large telescope. Photometry, which is easily performed with data gathered by small telescopes, only measures l (Buta & Smith 1979). McSwain et al. (2008) previously showed that NGC 3766, an open cluster in Centaurus, is rich with transient Be stars. In an effort to detect NRPs and study the formation of these transient disks, we are currently performing a long-term photometric study of the cluster. Here we present preliminary differential light curves that reveal magnitude variations of several Be stars that are consistent with NRPs.

3.3.3. Observations and Data Analysis We observed the cluster NGC 3766 using the CTIO 0.9m telescope and SITe 2048 CCD from 2008 March 19–24. The CCD was used in the quad readout mode without binning. We used Strömgren uvby filters and exposure times of 120, 20, 10, and 10 s, respectively. No additional standard stars were measured. Sky flats were used to calibrate the u and v filters, and dome flats were used for the b and y filters. The Strömgren uvby photometric data were zero-corrected and flat field-corrected using standard routines in IRAF using the quadred package. The daofind and phot procedures were used to automatically identify the stars and perform aperture photometry. We used the numbering scheme established by Ahmed (1962) and found in the WEBDA database to identify the stars. Differential magnitudes were determined for the variable Be stars identified in Balona & Engelbrecht (1986) and McSwain et al. (2008) and four check stars, Nos. 16, 95, 111, and 147. The check stars have constant differential magnitudes within the measured errors. Figure 1 (left) shows a differential light curve for the Be star No. 20 with variations in magnitude consistent with NRPs.

3.3.4. Results and Further Work Nineteen of the 25 Be stars measured at this preliminary stage have magnitude variations consistent with NRPs with periods on the order of several hours. For example, the u-band light curve of No. 20 was folded using a period of about 6.98 hours, shown in Figure 1 (right). Additional data collected at the CTIO 0.9m telescope in 2008 June, 2009 February, and 2009 May on NGC 3766 will be analyzed in conjunction with these data to perform a period search and identify the various periods that are present. In the future, we will construct a model for the non-radial pulsations that will allow theoretical light curves to be generated and compared to the observed light curves. Assuming slowly rotating stars, the non-radial pulsations can be modeled by spherical harmonic perturbations of a spherical stellar surface, given by Buta & Smith (1979) as

δR m m ıσmt ∼ A Y (θ, φ)e ` , R ` ` m where δR/R is the fractional change in radius, A` is the amplitude associated with spherical m m harmonic Y` (θ, φ), and σ` is the frequency of the mode. The most commonly observed mode of pulsation in Be stars is l = |m| = 2 (Rivinius, Baade, & Steﬂˇ 2003).

2012, Be Star Newsletter, 40 − 26 1.90 95

-u 1.95 20 u 2.00 1.25 1.90

1.30 95

-v 1.35 20 v 1.40 95

1.45 -u 0.90 1.95 20

u 0.95 95

-b 1.00 20 b 1.05 1.10 2.00

0.65 95

-y 0.70 20 y 0.75 0.80 44 46 48 50 52 0.0 0.2 0.4 0.6 0.8 1.0 HJD - 2454500 (days) PHASE

Figure 1. On the left, Str¨omgren uvby diﬀerential magnitudes are plotted for No. 20 in NGC 3766. On the right, the folded u-band light curve for No. 20 is plotted using a period of 6.98 hours. Representative error bars are shown in the upper right of each plot.

3.3.5. Acknowledgements We gratefully acknowledge travel support from the International Astronomical Union, the American Astronomical Society, and NASA DPR number NNX08AV70G. We also thank Charles Bailyn and the SMARTS Consortium for their help in scheduling these observations. We are also grateful for an institutional grant from Lehigh University and the U.S. Department of Education GAANN Fellowship.

References

Ahmed, F. 1962, Pub. Roy. Obs. Edinburgh, 3, 57 Balona, L. A., & Engelbrecht, C. A. 1986, MNRAS, 219, 131 Buta, R. J. & Smith, M. A. 1979, ApJ, 232, 213 De Ridder, J. 2001, Ph.D. thesis, Katholieke Univ. Leuven Guti´errez-Soto,J., Fabregat, J., Suso, J., Lanzara, M., Garrido, R., Hubert, A.-M., & Floquet, M. 2007, A&A, 476, 927 McSwain, M. V., Huang, W., Gies, D. R., Grundstrom, E. D., & Townsend, R. H. D. 2008, ApJ, 672, 590 Porter, J. M., & Rivinius, T. 2003, PASP, 115, 1153 Rivinius, T., Baade, D., & Steﬂ,ˇ S. 2003, A&A, 411, 229

3.4. Analysis of B and Be star populations of the double cluster h and χ Persei Amber N. Marsh1, M. Virginia McSwain1, and Thayne Currie2 1Lehigh University, Department of Physics, 16 Memorial Drive E, Bethlehem, PA, USA; email: [email protected], [email protected] 2Harvard - Smithsonian Center for Astrophysics; email: [email protected] Received: 2009 October 29; Accepted: 2010 February 5.

2012, Be Star Newsletter, 40 − 27 3.4.1. Introduction NGC 869 and NGC 884 (h and χ Persei, respectively) are a well known double cluster rich in massive B-type stars, and have been the focus of many studies over the years. Recent studies show that NGC 869 and NGC 884 have nearly identical ages of ∼ 13–14 Myr, common distance moduli of dM ∼ 11.85, and common reddenings of E(B-V) ∼ 0.5–0.55 (Currie et al. 2009; Slesnick et al. 2002; Bragg & Kenyon 2005). Currie et al. (2008) (hereafter C08) identified two populations of NGC 869 and NGC 884 stars with detected Spitzer MIPS-24 µm excess emission: 20 A and F-type stars with luminous debris disk emission and 57 brighter, earlier stars with weaker excess emission. They identify most of the latter group as candidate Be stars. However, only 21 were previously listed as Be stars (e.g. Bragg & Kenyon 2002; Slesnick et al. 2002). Currie et al. (2010) find evidence for some variable reddening across the clusters however, this does not deviate substantially from the median reddening values they adopt for the cluster cores; E(B-V)=0.55 for NGC 869 and E(B-V)=0.52 for NGC 884. Their spectroscopic analysis does not indicate a separate population of cluster members which have an extinction that differs significantly from the rest of the population. In this study, we analyze blue optical spectra of 92 early-type cluster members, including 16 candidate Be stars from C08, and investigate their near-to-mid infrared (IR) excesses. With continued monitoring of these stars in the both the optical and IR regimes, we hope to explore these excesses as a reasonable means for identifying potential Be stars within clusters, as well as to investigate the transient natures of the disks surrounding the known Be stars in NGC 869 and NGC 884.

3.4.2. Overview Blue optical spectra of 92 members of NGC 869 and NGC 884 were taken on 2005 Nov. 14–15 using the WIYN 3.5m telescope with the Hydra spectrograph. The observed spectra cover the wavelength range 4250–4900 A.˚

Model spectral fits were used to measure values for V sin i, Teff , and log g for B-type stars. V sin i was determined by comparing the He I λλ4387, 4471, 4713, and Mg II λ4481 lines with the Kurucz ATLAS9 models (Kurucz 1994) and taking a weighted average of these four values. For stars having Teff ≥ 15000 K, the TLUSTY BSTAR2006 models (Lanz & Hubeny 2007) were used to find Teff and log g using the Hγ line. For stars having Teff ≤ 15000 K, the Kurucz ATLAS9 models were used (Kurucz 1994). The method of Huang & Gies (2006) (hereafter HG06) was used to determine log gpolar. For Be stars, Strömgren photometry available from the WEBDA database was used to derive Teff and log gpolar based on the methods of McSwain et al. (2008). The masses and radii for all stars were determined from the Schaller et al. (1992) evolutionary tracks, which are shown plotted with Teff and log gpolar in Figure 1.

3.4.3. Results Sixteen Be candidates from C08 are present in our sample or that of HG06. Three of these 16 stars (Nos. 869-566, 869-1162, 884-2468) show no evidence of circumstellar emission in our spectra, though all have been observed to be Be stars in the past (Keller et al. 2001). Ten of the C08 Be candidates in our spectra do show emission. Stellar parameters for the remaining 3 candidates are found in HG06, thus we cannot comment on the presence of emission. In addition, we ﬁnd Be emission in one star (No. 1772) that was not observed

2012, Be Star Newsletter, 40 − 28 Figure 1. For both NGC 869 (left) and NGC 884 (right), Teﬀ and log gpolar are plotted with the evolutionary tracks of Schaller et al. (1992). The ZAMS mass of each evolutionary track is labeled along the bottom. Normal B-type stars are shown as open diamonds while Be stars are ﬁlled diamonds.

by C08, and we present results for one additional star (No. 1268) identiﬁed as a Be star by Keller et al. (2001). These results are summarized in Table 1.

Table 1. Measured physical parameters for Be stars

Cluster- V sin i Teﬀ log gpolar M? R? Be 1 −1 2 Star (km s ) (K) (dex) (M )(R ) Cand. Comment Ref. NGC 869-49 172 23757 3.63 12.3 8.9 Y Emission present This work NGC 869-517 178 - - - - Y Emission present This work NGC 869-566 306 21183 3.57 10.4 8.7 Y No emission present3 This work NGC 869-846 205 22747 3.29 14.7 14.3 Y Weak emission present This work NGC 869-847 87 27000 3.54 17.8 11.8 Y Weak emission present This work NGC 869-1162 66 19175 2.40 33.6 60.8 Y No emission present3 This work NGC 869-1261 285 26065 3.93 12.0 6.2 Y Strong emission present This work NGC 869-1268 151 24491 3.48 14.8 11.6 N No emission present3,4 This work NGC 869-1278 197 24562 4.32 9.0 3.4 Y Emission present This work NGC 884-1772 379 - - - - - Emission present This work NGC 884-1926 106 27190 3.92 13.5 6.7 Y Strong emission present This work NGC 884-2091 236 - - - - Y Emission present This work NGC 884-2138 153 23579 3.63 12.0 8.7 Y Emission present This work NGC 884-2165 79 26571 4.03 11.9 5.5 Y – HG06 NGC 884-2402 141 28238 3.81 15.6 8.1 Y – HG06 NGC 884-2468 134 10500 4.11 2.7 2.4 Y No emission present3 This work NGC 884-2563 308 25820 4.18 10.7 4.4 Y Strong emission present This work NGC 884-2949 168 18240 3.96 6.4 4.4 Y – HG06

Notes: 1 Identiﬁcation numbers from the WEBDA database. 2 Be candidate in C08. 3 Stars not showing emission in our observations are likely transient Be stars. 4 Identiﬁed as Be star by Keller et al. (2001).

Spectral energy distributions (SEDs) for two stars in NGC 884 and one star in NGC 869 are displayed in Figure 2. UBV magnitudes are from the WEBDA database, JHKs are from the 2MASS survey, and Spitzer [8] and [24] µm are from C08. These magnitudes were then converted to ﬂuxes via the methods detailed in Bessell et al. (1998); Cohen et al. (2003); Colina et al. (1996); Reach et al. (2005); Rieke et al. (2008). Assuming a constant E(B −V ) = 0.52 for NGC 869 and NGC 884 (Bragg & Kenyon 2005; Slesnick et al. 2002), reddened blackbody curves have been overlaid with these plots to investigate their near-to-mid IR excesses. All three stars shown in Figure 3 are proposed Be candidates (C08), with NGC

2012, Be Star Newsletter, 40 − 29 884-2138 and NGC 869-49 having emission present in our optical spectra and observed near-to-mid IR excess. NGC 884-2165 is not in our spectroscopic sample but has previously been identiﬁed as a Be star and has observed IR excess (Keller et al. 2001).

Figure 2. SEDs for two stars in NGC 884 and one star in NGC 869. Reddened blackbody curves are overlaid with these plots to investigate their near-to-mid IR excesses.

3.4.4. Conclusions and Further Work We have measured the physical parameters of 77 B-type stars and 15 Be stars in NGC 896 and NGC 884. Sixteen Be candidates from C08 are present in our sample or that of HG06. Of these 16 Be candidates, 3 stars show no evidence of emission in our optical data and are likely transient Be stars. Ten of these Be candidates do show emission in our spectra. Those Be candidates without emission in our spectra should be monitored in the future to further investigate their transient nature. In the future, IRAC 3.6-5.8 µm data will be combined with the optical and IR fluxes used here to investigate the observed SEDs. We will fit the new SEDs using modern flux models rather than blackbody curves. Modifications accounting for variable reddening throughout the clusters will also be made. These new SED fits can then be used to model the Be disk sizes and temperatures.

3.4.5. Acknowledgments We would like to thank the referee, Carol Jones, for her insightful comments which greatly improved this manuscript. We are grateful for travel support provided by the American Astronomical Society and the International Astronomical Union. We would like to thank Yale University for providing access to the WIYN telescope at KPNO. Institutional support was provided by Lehigh University. This work was also supported by NASA DPR number NNX08AV70G.

2012, Be Star Newsletter, 40 − 30 References

Bessell, M. S., Castelli, F., & Plez, B. 1998, A&A, 333, 231 Bragg, A., & Kenyon, S. 2002, AJ, 124, 3289 Bragg, A., & Kenyon, S. 2005, AJ, 130, 134 Cohen, M., Wheaton, Wm. A., & Megeath, S. T. 2003, AJ, 126, 1090 Colina, L., Bohlin, R. C., & Castelli, F. 1996, AJ, 112, 307 Currie, T., Hernandez, J., Irwin, J., Kenyon, S. J., Tokarz, S., Balog, Z., Bragg, A., Berlind, P., & Calkins, M. 2010, ApJS, 186, 191 Currie, T., Evans, N. R., Spitzbart, B. D., Irwin, J., Wolk, S. J., Hernandes, J., Kenyon, S. J., & Pasachoﬀ, J. M. 2009, AJ, 137, 3210 Currie, T., Kenyon, S. J., Balog, Z., Rieke, G., Bragg, A., & Bromley, B. 2008, ApJ, 672, 558 Huang, W., & Gies, D. R. 2006, ApJ, 648, 591 Keller, S. C., Grebel, E. K., Miller, G. J., & Yoss, K. M. 2001, AJ, 122, 248 Kurucz, R. L. 1994, Kurucz CD-ROM 19, Solar Abundance Model Atmospheres for 0, 1, 2, 4, 8 km/s (Cambridge: SAO) Lanz, T., & Hubeny, I. 2007, ApJS, 169, 83 McSwain, M. V., Huang, W., Gies, D. R., Grundstrom, E. D., & Townsend, R. H. D. 2008, ApJ, 672, 590 Reach, W. T., Megeath, S. T., Cohen, M., Hora, J., Carey, S., Surace, J., Willner, S. P., Barmby, P., Wilson, G., Glaccum, W., Lowrance, P., Marengo, M., & Fazio, G. G. 2005, PASP, 117, 978 Rieke, G. H., Blaylock, M., Decin, L., Engelbracht, C., Ogle, P., Avrett, E., Carpenter, J., Cutri, R. M., Armus, L., Gordon, K., Gray, R. O., Hinz, J., Su, K., & Willmer, C. N. A. 2008, AJ, 135, 2245 Schaller, G., Schaerer, D., Meynet, G., & Maeder, A. 1992, A&AS, 96, 269 Slesnick, C., Hillenbrand, L. A., & Massey, P. 2002, ApJ, 576, 880

2012, Be Star Newsletter, 40 − 31 4. WHAT’S HAPPENING?

4.1. A new bright outburst of the Be star mu Centauri Sebasti´anA. Otero Asociaci´onCielo Sur (CEA) & Grupo Wezen 1 88, Buenos Aires, Argentina email: [email protected] Received: 2009 July 2; Accepted: 2009 July 2

After several years of relatively low activity in the visual band, mu Centauri woke up in 2006 with a bright outburst (V = 3.08) (Otero, 2006). Another outburst took place a year later reaching V = 3.13 (Otero, 2007). After being in a very faint quiescent state (mean magnitude between V = 3.5 and 3.6 just prior ot the current outburst), mu Cen has rapidly risen to a new maximum. The most recent visual observations by S. Otero are: 2009, June 13.240, V = 3.54 2009, June 13.985, V = 3.55 2009, June 22.906, V = 3.52 2009, June 24.996, V = 3.52 2009, June 25.912, V = 3.51 2009, June 28.057, V = 3.28 2009, July 02.164, V = 3.20

Figure 1. Mu Centauri light curve since January 2009 including the current outburst. Visual observations by Otero.

Updated lightcurves of this and past outbursts: http://ar.geocities.com/varsao/Curva Mu Cen.htm Conﬁrmatory spectroscopic observations are encouraged. References: Otero, S. 2006, The Be Star Newsletter, Vol. 38, http://www.astro.virginia.edu/∼dam3ma/benews/volume38/whap/otero0.html Otero, S. 2007, The Be Star Newsletter, Vol. 38, http://www.astro.virginia.edu/∼dam3ma/benews/volume39/whap/otero0.html

2012, Be Star Newsletter, 40 − 32 4.2. IAU Symposium 272: “Active OB stars: structure, evolution, mass loss, and critical limits” (First Announcement) C. Neiner GEPI, Observatoire de Paris, CNRS, UniversitéParis Diderot; 5 place Jules Janssen, 92190 Meudon, France First announcement: Early-type (OB) stars dominate the ecology of the universe as cosmic engines via their extreme output of radiation and matter, not only as supernovae but also during their entire lifetimes with far-reaching consequences. Active OB stars are massive and intermediate- mass stars that display strong variability on various time scales due to such phenomena as mass outflows, rapid rotation, pulsations, magnetism, binarity, radiative instabilities, and the influence of their circumstellar environment. This concerns in particular classical and Herbig Be, Bp, β Cep, Slowly Pulsating B Stars (SPB), B[e] and O stars, as well as massive binaries such as the Be X-ray binaries and those that harbor O-type subdwarf companions. The IAU Symposium 272 will be dedicated to discussion of the structure, evolution, mass loss, and critical limits of active early-type stars, four axes of research that are currently providing important clues about the physics of these objects. We expect that the meeting will allow fruitful exchange by bringing together scientists working in the fields of O stars, B stars, Bp stars, Be stars and Herbig Be stars, at wavelengths that span the electromagnetic spectrum (especially X-ray, UV, optical, and IR) with emphasis on forefront observational techniques (e.g. spectropolarimetry, interferometry, asteroseismology). We thus expect that the meeting will result in further important progress in our understanding of active OB stars and give rise to new projects that will be undertaken in the second decade of the 21st century. The key topics of the IAU Symposium 272 are:

• the internal structure of active OB stars: pulsations, rotation, magnetism, transport processes • their evolution: stellar environment, formation, binaries, late stages (including magnetars and GRBs) • their circumstellar environment: disks, magnetospheres, the Be phenomenon, wind, clumping • active OB stars as extreme condition test beds: critical rotation, mass loss, radiation ﬁelds • ’normal’ OB stars as calibrators: fundamental parameters, astronomical quantities • populations of OB stars: population studies, tracers of galactic structure, cosmic history

The IAU Symposium 272 will be held in Paris from July 19 to 23, 2010. Pre- registrations are open at http://iaus272.obspm.fr for those who wish to receive further information. The website also provides details about the Symposium scientiﬁc topics and local information. For further inquiries please contact [email protected]. The symposium is co-sponsored by the IAU and the Paris Observatory. We are looking forward to seeing you in Paris in 2010! Coralie Neiner, for the SOC

2012, Be Star Newsletter, 40 − 33 4.3. Post-doc position in observational studies of massive stars at Uni- versidad de Valparaiso, Chile Michel Cure Departamento de Fisica y Astronomia, Facultad de Ciencias, Universidad de Valparaiso, Av. Gran Bretana 1111, Casilla 5030, Valparaiso, Chile

The Department of Physics and Astronomy of the Universidad de Valparaiso, Chile, invites applications for a postdoctoral position for an observational astronomer in the ﬁeld of massive stars. The main goal of this project is to improve our knowledge related to the structure of circumstellar disks, formed from material ejected by massive and fast rotating stars, through an integrated observational plus theoretical approach in collaboration with Dr. Lydia Cidale (La Plata, Argentina) and Dr. M. Kraus (Ondrejov, Czech Republic). This work will focus on the analysis of the wind properties and the circumstellar geometry of objects showing the Be or B[e] phenomenon, using mainly data originating from the GEMINI-South facilities. The position is for two years. The starting date should be from March 1, 2010. The successful candidate will have full access to the 10% of Chilean observing time at the international telescopes operating in Chile, as ESO (VLT and La Silla), APEX, Gemini South, SOAR, Magellan, and to the other telescopes at Cerro Tololo and Las Campanas observatories. Valparaiso is, together with the neighboring town Vi˜nadel Mar, the most important ur- ban center of Chile, outside the capital Santiago. It also hosts one of the largest con- centrations of Universities in Chile. The Universidad de Valparaiso has recently created a rapidly growing research group in astrophysics which currently numbers seven professors (http://www.dfa.uv.cl). Informal enquiries are welcomed and should be made to Professor Dr. Michel Cure ([email protected]). Applicants should send, before Dec. 31, 2009, and by e-mail, their CV, publication list, statement of research interests, and arrange for two letters of recommendation.

4.4. JOB OFFER FOR 2 PERMANENT POSITIONS: University of Guanajuato Philippe Eenens Department of Astronomy, University of Guanajuato, Mexico

Dear Colleague, At the Department of Astronomy of the University of Guanajuato, Mexico, we need to ﬁll immediately two PERMANENT POSITIONS in the areas of Stellar Atmospheres and/or Cosmology. If you know someone who could be interested, could you please draw this announcement to their attention? Thank you. The applicants should meet the following REQUIREMENTS:

1. Have a PhD in Astrophysics.

2012, Be Star Newsletter, 40 − 34 2. Have academic experience preferably in the Areas of cosmology or Stellar Atmo- spheres, but good candidates from other areas of astrophysics will also be considered. 3. Have experience in teaching with positive teacher evaluation. 4. Have refereed publications. 5. Submit in free format a written research project to carry on any subject of interest mentioned. 6. Be able to qualify for membership in the Mexican National Research System in the near future is considered highly desirable. 7. Submit the following documentation to the Chairman of Committee of Income and Permanence: (a) Letter of application with description of motivation, agreeing to participate in this call in the terms and conditions set out therein, and stating postal address, email address, phone and the best means to establish contact with the applicant. (b) Curriculum vitae, attaching supporting documents substantiating the academic training, career, activities and achievements. (c) Two letters of professional recommendation. 8. Be available immediately to join the academic activities of the Department.

ACTIVITIES TO FULFILL:

1. Fill the four essential functions of the University set out in Organic Law of the Uni- versity of Guanajuato: research, teaching, institutional life and outreach. 2. Conduct original, frontier research, and so strengthen the Area, and seek ﬁnancial resources for developing this activity. 3. Teach courses at undergraduate and postgraduate level as required. 4. Supervise thesis work. 5. Participate in the Institutional Program of Academic Tutoring for students of the University. 6. Participate in institutional life. 7. Participate in academic administration as may be assigned within the Institution. 8. Undertake public outreach activities.

The city of Guanajuato is a quiet, safe, colonial city in Central Mexico. DEADLINE FOR RECEPTION OF DOCUMENTS: 15 of November POSITIONS AVAILABLE IMMEDIATELY For more information, write to Philippe Eenens: [email protected] .

2012, Be Star Newsletter, 40 − 35 4.5. Announcement: Kick-oﬀ of GREAT working group on Stellar Vari- ability with Gaia Joris De Ridder K.U.Leuven, Belgium

GREAT (Gaia Research for European Astronomy Training) is an approved European Sci- ence Foundation (ESF) network programme that aims to build scientific collaborations across Europe to exploit the avalanche of Gaia data, and to deliver the major scientific advances around the main objectives of Gaia. The programme will provide funding for training events, workshops, major conferences, proceedings, grants for short and exchange visits, and outreach material. Already about 90 research groups from 17 countries across Europe have shown interest to participate in this large network. GREAT defines several working groups, including a working group dedicated to stellar variability. Gaia is predicted to discover millions of new variable stars, for which it not only will provide photometric time series, but also their 3D position in our Milky Way. The goals of this working group are to explore which synergies exist between the different research groups, to define and to set up new collaborations that will optimally exploit the Gaia data, to discuss and prepare for complementary ground-based follow-up, and to define interesting workshops, training events and/or conferences related to Gaia and stellar variability for the coming years. Researchers from European institutes interested in participating in this working group, are invited to email their name and institute to the WG’s co-facilitator Joris De Ridder ([email protected]). Relevant links:

• GREAT: http://www.ast.cam.ac.uk/GREAT/index.html

• GAIA: http://www.esa.int/esaSC/120377 index 0 m.html

4.6. Periodic behavior of the He I 6678 emission in δ Sco Ernst Pollmann Emil-Nolde-Straße 12, 51375 Leverkusen, Germany email: [email protected] Received: 2010 February 9; Accepted: 2010 April 6

δ Sco is a binary system with an eccentric orbit which is exhibiting a strong mass loss that has resulted in a circumstellar gaseous disk formation. This study of a correlation between Hα and He I 6678 equivalent widths (EWs) and the He I 6678 line proﬁles have been performed at the observatory of the “Vereinigung der Sternfreunde K¨oln”(Germany) with a 0.4 m Schmidt-Cassegrain-telescope C14. A classical slit-grating-spectrograph with a spectral resolving power R∼14000 and a CCD-camera (768 × 512 pixel, pixel size 9µm) provides spectra within the range from 6500 to 6700 A.˚ The spectra have been reduced manually with the programs VSpec and MK32. A high signal-to-noise ratio (as a rule

2012, Be Star Newsletter, 40 − 36 > 400) is necessary to obtain simultaneous information about the strength and line proﬁle behaviour of Hα and the double-peak emission line of He I 6678. Following the generally accepted assumption that the disk of this binary system is being fed in a kind of outbursts (Miroshnichenko et al. 2003), and since the He I 6678 line forms near the photosphere of the primary component one can expect a correlation between the equivalent width of the Hα and He I 6678 lines (Fig. 1). Such a correlation might be interpreted as a result of a disk feeding process. However on the other hand we can not exclude, that this reﬂects only contemporaneous density variations within the line formation zones.

Figure 1. Correlation between the equivalent width of He I 6678 and Hα from 04/2005 to 08/2009.

Since April 2005, during every observing season, the observed correlation impressively sup- ports the existence of this disk-feeding process, in which the slope of the linear fit shown in Fig. 1 reflects the quantitative correlation. In addition to the analysis of the EWs measured in the same spectra, the He I 6678 line double-peaked profile exhibits a variable V/R ratio. For the first time it was possible to monitor the entire cycle of the V/R variations in 2009 (Fig. 2). In the earlier seasons, merely the descent could be measured. On this occasion I would like to emphasize particularly that, amongst others, members of the French group, ARAS (http://www.astrosurf.com/aras), made a significant contribution to the frequent observations. The V/R measurements of the five cycles presented here permitted an analysis of its possible periodicity (Fig. 2). Thom Gandet, Thomas Rivinius, and Ernst Pollmann independently calculated the following periods: Gandet: 535 d ± 5 d Rivinius: 536 d ± 4 d Pollmann: 541 d ± 15 d

2012, Be Star Newsletter, 40 − 37 (a)

(b)

(c)

Figure 2. Plots of the periodogram analysis with program AVE (a) V/R-time behaviour (b) Periodogram of the data shown in Fig. 2a (c) Phase plot of the data shown in Fig. 2a

2012, Be Star Newsletter, 40 − 38 The ephemerides of the V/R variability are the following: JD 2453420 (± 8-12) + 535 × E (Gandet) JD 2453935 (± 10) + 541 × E (Pollmann) The V/R ratio has been measured only in the spectra for which both peaks are apparent. In the observations reported here, the triple peak structures were observed on the following dates: 2006: 04/02, 05/02, 05/11, 06/02, 06/23, 06/29, 07/02, 08/13, 08/18 2009: 05/29, 06/13, 06/19, 06/21, 07/04, 07/12/ 07/18. An inspection of the V/R phase curve shows that the third emission component was observed only within the phase interval ∼0.67 to ∼1.1 (see Fig. 3). This might be due to the presence of a density enhancement in front of the star and hidden behind it at other phases.

Figure 3. Examples of the He I 6678 line proﬁle labeled with observing dates and the V/R cycle phases.

Reference Miroshnichenko, A. S., et al. 2003, A&A, 408, 305-311

2012, Be Star Newsletter, 40 − 39 4.7. Research Position at the Stellar Department Ondrejov Jiˇr´ıKub´at Astronomical Institute, Fricova 298, 251 65 Ondrejov, Czech Republic email: [email protected]

The Astronomical Institute of the Academy of Sciences of the Czech Republic opens one temporary position in its Stellar department in the field of stellar radiative transfer and hydrodynamics to work on a project “Mass loss rate predictions for hot stars”. The applicant is expected to have experience in the field of the proposed project and to have a university degree, preferably PhD, at the time of arrival. The Stellar Department of the Astronomical Institute is located on the observatory campus in Ondrejov, which is situated approximately 30 km south-east of Prague. The stellar department operates a 2m telescope with a coude spectrograph, which is suitable for studies of bright objects (e.g., B stars, hot subdwarfs). Czech Republic is a member state of both ESO and ESA, and have access to ESO facilities. The department includes about a dozen active researchers, with a total of about 60 scientists working at the As- tronomical Institute. The department offers excellent computing facilities, running under Linux. Researchers of the stellar department also have free access to the computer cluster (http://wave.asu.cas.cz/ocas/). The salary will be based on the standard domestic scale. The starting date is as soon as possible and the appointment is initially for 1 year. Further extension will be possible upon satisfactory scientific results, publication output, and availability of funding. The candidates should send their applications (list of publications, curriculum vitae, and summary of their research work) and two letters of recommendation to Dr. J. Kubat Astronomical Institute Fricova 298 251 65 Ondrejov Czech Republic phone +420 323620328 fax +420 323620250 e-mail: [email protected] . Research Position URL: http://www.asu.cas.cz/news/215 research-position/ Applications should be received before 31st May 2010.

4.8. IAU Symposium 272: “Active OB stars: structure, evolution, mass loss, and critical limits” (Final Announcement) C. Neiner GEPI, Observatoire de Paris, CNRS, Universit´eParis Diderot; 5 place Jules Janssen, 92190 Meudon, France email: [email protected] Received: 28 May 2010 Final announcement: The IAU Symposium 272 will be dedicated to discussion of the structure, evolution, mass loss, and critical limits of active early-type stars. We expect that the meeting will allow

2012, Be Star Newsletter, 40 − 40 fruitful exchange by bringing together scientists working in the ﬁelds of O, B, β Cep, SPB, Bp, Be, B[e], and Herbig Be stars, at wavelengths that span the electromagnetic spectrum (especially X-ray, UV, optical, and IR) with emphasis on forefront observational techniques (e.g. spectropolarimetry, interferometry, asteroseismology). The key topics of the IAU Symposium 272 are:

• the internal structure of active OB stars • their evolution • their circumstellar environment • active OB stars as extreme condition test beds • ’normal’ OB stars as calibrators • populations of OB stars

The IAU Symposium 272 will be held in Paris from July 19 to 23, 2010. The DEADLINE for registration to the symposium, abstract submission, and registration to social events at http://iaus272.obspm.fr is VERY SOON: *** JUNE 1 *** The symposium is co-sponsored by the Ile de France region, IAU, INSU, the Ministry for High Education and Research, PNPS, the GEPI laboratory, the Paris Observatory, A&A, and EDP Sciences. We are looking forward to seeing you in Paris in July! Coralie Neiner, for the SOC

4.9. Post-doctoral Position at the University of SãoPaulo, Brazil Alex C. Carciofi Instituto de Astronomia, Geof´ısicae CiênciasAtmosféricas,Universidade de SãoPaulo, Rua do Matão1226, Cidade Universitária,05508-900, SãoPaulo, SP, BRAZIL email: [email protected]

Applications are invited for a Fapesp-funded post-doctoral scholarship at the Astronomy De- partment of University of SãoPaulo to work on models of circumstellar disks and outflows, with emphasis on Be stars, in the context of an integrated observational and theoretical effort in collaboration with Drs. Thomas Rivinius, Stanislav Stefl and Dietrich Baade (ESO) and Dr. Atsuo Okazaki (Hokkai-Gakuen University, Japan). The University of SãoPaulo is one of the most important research institutes in Latin America. The Astronomy Department has a consolidated research tradition in many astrophysical fields and currently has 38 professors, about 50 PhD students, 30 MS students and 25 post-docs from many different countries. Fapesp post-doctoral scholarship is of about US $2,800 per month, free of taxes, plus a research grant of about US $5,000 per year. Travel and moving expenses are also included (one month extra salary plus plane tickets). The position is funded for up to two years. A PhD degree and relevant research experience are required.

2012, Be Star Newsletter, 40 − 41 Because the post-doctoral scholarship of Fapesp are awarded to the research project, the application process will have two phases: * Phase 1 (Deadline 07/31/2010) Selection of one candidate among the applicants based on their CV, publication record, and research expertise. * Phase 2 (Deadline 08/30/2010) Submission of a research project to Fapesp, written by both the successful candidate of phase 1 and the supervisor (Alex C. Carcioﬁ). Applicants for phase 1 are invited to contact Alex C. Carcioﬁ by email ([email protected]) before July 31st, 2010. The requirements for phase 1 application are: CV, publication list, and a statement of research interests.

4.10. The end of an active Be state in 66 Oph

A. S. Miroshnichenko1, S. V. Zharikov2, J. Fabregat3, D. E. Reichart4, K. M. Ivarsen4, J. B. Haislip4, M. C. Nysewander4, and A. P. LaCluyze4 1 Department of Physics and Astronomy, University of North Carolina at Greensboro, Greensboro, NC 27402, USA (http://www.uncg.edu/∼a mirosh/) 2 Instituto de Astronom´ıa,Universidad Nacional Autónomade México,Apartado Postal 877, 22830, Ense- nada, Baja California, México 3 Observatorio Astronómicode la Universidad de Valencia, Calle CatedráticoAgust´ınEscardino 7, 46980 Paterna, Valencia, Spain 4Department of Physics and Astronomy, University of North Carolina, Chapel Hill, NC 27599, USA Received: 18 February 2011; Accepted: 18 March 2011

The main feature of a star or a stellar system with the Be phenomenon is a circumstellar gaseous disk that is responsible for emission lines in its spectrum. The line emission is variable and can disappear completely for some time. Numerous cases of transition from a Be to a normal B-type state and back have been reported, but only a few of them were well documented (e.g., µ Cen, δ Sco, and π Aqr, Peters 1979, Miroshnichenko et al. 2001, and Bjorkman et al. 2002, respectively). A normal B-type state has been found to be accompanied by no infrared excess, which is always observed during an active Be state. This suggests that the circumstellar material almost completely vanishes when such a transition occurs. Observations of a Be star in a normal B-type state therefore present an opportunity to measure true fundamental parameters, which are masked by the disk during an active Be state. Here we report our detection of a disk loss by 66 Oph, a well-studied object that has spent the last ∼50–60 years in an active Be state. 66 Oph was ﬁrst mentioned to exhibit Balmer lines in emission by Merrill & Burwell (1933). Sparse observations in the 1930s – 1960s indicated a variable emission-line spectrum with a minimum occurring in mid 1950s which can be considered as the onset of the active Be state. The emission-line strength was steadily increasing until 1993 and decreasing since then (Floquet et al. 2002). A maximum equivalent width (EW) of the Hα line of 60 A˚ was observed by Hanuschik et al. (1995). Silaj et al. (2010) reported a weak Hα line with an EW of 3.6 A˚ in 2007. Granada, Arias, & Cidale (2010) observed weak infrared hydrogen emission lines in August 2008 and suggested that the active Be state might be coming to an end. 66 Oph is a recognized binary system with a secondary component detected by interferome-

2012, Be Star Newsletter, 40 − 42 try (Mason et al. 2009) and direct imaging in the K-band (Oudmaijer & Parr 2010). Radial velocity variations were detected in its spectrum long ago by Struve (1925), but no orbital period has been determined from these and later spectroscopic data. Floquet et al. (2002) concluded on the existence of non-radial pulsations in the primary component and derived its fundamental parameters (Teff = 23850±900 K and log g = 3.95 ± 0.08) using the optical light curve and the Balmer jump data. These authors used a photospheric brightness of V = 4.85 mag and a color-excess of E(B−V ) = 0.18 ± 0.06 mag from the λ2175 A˚ graphite UV interstellar extinction band. Steflˇ et al. (2004) found that the secondary component of 66 Oph is a close binary itself and pointed out that this might cause systematic errors in determination of the primary’s fundamental parameters. Therefore, the system’s properties are worth revisiting, and a normal B-type state with no complicating effects due to circumstellar matter is a good time for such a study. We took photometric UBVRI observations of 66 Oph on April 4, 11, and 19, 2010 using two 0.4-m robotic PROMPT telescopes (Reichart et al. 2005) and JHKL observations on April 7, 2010 using a 0.75-m telescope at the SAAO. Optical spectroscopic observations were obtained on October 15, 2010 with an échelle spectrograph at the 2.1-m telescope of the San Pedro Martir Observatory in Mexico with a spectral resolving power of R ∼ 20, 000 between ∼4000 and 6800 A.˚ We have found virtually no signs of the line emission and the IR excess (see Fig. 1).

Figure 1. Left panel: Balmer lines in the spectrum of 66 Oph on October 15, 2010. Hα is shown by the solid line, Hβ is shown by the dashed line. Intensity is normalized to the nearby continuum, radial velocity is heliocentric. Telluric lines were not removed from the Hα region. Right panel: Spectral energy distribution of 66 Oph in April 2010. The circles show our UBVRIJHKL data with the interstellar reddening removed using E(B−V )=0.18 mag and the average Galactic reddening law from Savage & Mathis (1979). The solid line shows a Kurucz (1993) model atmosphere for Teﬀ = 24000 K and log g = 4.0. The observed ﬂuxes are normalized to that in the V -band.

The strength of the diﬀuse interstellar bands at λ5780 and λ5797 A˚ in our spectrum and the color-index (B−V ) = −0.06 ± 0.02 mag in our photometric data allowed us to determine the color-excess E(B−V ) that coincided with the UV result quoted above. The V -band brightness in our data, 4.85 mag, also coincided with the brightness level assumed by Floquet et al. (2002) for the photosphere. At the same time, the near-IR brightness (e.g., K = 5.17 mag) was at the faintest level ever detected from the object (compare with K = 4.00 mag in 1980, Ashok et al. 1984). A more detailed study of the declining phase of the active Be state of 66 Oph will be presented elsewhere.

2012, Be Star Newsletter, 40 − 43 A weak emission component near the bottom of the Hα line manifests that the circumstellar matter is still present in the system. It may either belong to the debris of the former disk around the primary component or be located near the secondary component, as was found in the binary system of π Aqr when its primary component has lost its disk (Bjorkman et al. 2002). In the latter case, monitoring the motion of this remaining emission may lead to constraining the yet unknown secondary’s orbit. The 2011 observing season can be very important for further studies of 66 Oph and the Be phenomenon in whole. Observations of π Aqr showed that the primary’s circumstellar disk has shown no signs of recovery for at least five years. If this is the case for 66 Oph, there will be enough time to search for radial velocity variations in order to constrain the system properties. Closely watching the disk-less state will get us more insights into reasons for the disk renewal as well. We propose to monitor 66 Oph starting in the summer of 2011 for at least a few years or until the new active state begins. The campaign should include moderately high-resolution optical spectroscopy (R ≥ 10000) as well as optical/near-IR photometry, both as frequent as a few times a month. A webpage is set up to coordinate efforts of both professionals and amateurs (Miroshnichenko 2011). References: Ashok, N.M., Bhatt, H.C., Kulkarni, P.V., & Joshi, S.C. 1984, MNRAS, 211, 471 Bjorkman, K.S., Miroshnichenko, A.S., McDavid, D.A., & Pogrosheva, T.M. 2002, ApJ, 573, 812 Floquet, M., Neiner, C., Janot-Pacheco, E., et al. 2002, A&A, 394, 137 Granada, A., Arias, M.L., & Cidale, L. 2010, AJ, 139, 1983 Hanuschik, R.W., Hummel, W., Dietle, O., & Sutorius, E. 1995, A&A, 300, 163 Kurucz, R.L. 1993, Smithsonian Astrophys. Observ., CD-ROM No. 13 Mason, B.D., Hartkopf, W.I., Gies, D.R., et al. 2009, AJ, 137, 3358 Merrill, P.W., & Burwell, C.G. 1933, ApJ, 78, 87 Miroshnichenko, A.S., Fabregat, J., Bjorkman, K.S., et al. 2001, A&A, 377, 485 Miroshnichenko, A.S. 2011, http://www.uncg.edu/∼a mirosh/66Oph/ Oudmaijer, R.D., & Parr, A.M. 2010, MNRAS, 405, 2439 Peters, G.J. 1979, ApJS, 39, 175 Reichart, D.E., Nysewander, M., Moran, J., et al. 2005, Nuovo Cimento C, 28, 767 Savage, B.D., & Mathis, J.S. 1979, ARA&A, 17, 73 Silaj, J., Jones, C.E., Tycner, C., et al. 2010, ApJS, 187, 228 Stefl,ˇ S., Hadrava, P., Baade, D., et al. 2004, in Stellar Rotation, Proc. IAU Symp. 215, (eds.) A. Maeder & P. Eenens, p. 166 Struve, O. 1925, ApJ, 62, 434

4.11. Post-doctoral position in B[e] star research Michaela Kraus Astronomical Institute AVCR, v.v.i., Fricova 298, 251 65 Ondrejov, Czech Republic

Applications are invited for a post-doctoral position in the Stellar Physics Department of the Astronomical Institute. The successful applicant will work with Dr. Michaela Kraus on the disks and winds of B[e] stars. The applicant should have experience with observations (spectroscopy and/or interferometry), data reduction, and data analysis of optical and/or

2012, Be Star Newsletter, 40 − 44 infrared data and have a background in massive star evolution, stellar winds, and circumstellar disks. The applicant should have a university degree, preferably PhD, at the time of arrival. The Stellar Physics Department of the Astronomical Institute is located on the observatory campus in Ondrejov, which is situated approximately 30 km south-east of Prague. The stellar department operates a 2m telescope with a coude spectrograph, which is suitable for studies of bright objects (e.g., B-type stars). Czech Republic is a member state of both ESO and ESA, and has access to ESO facilities. The department includes about a dozen active researchers, with a total of about 60 scientists working at the Astronomical Insititute. The department oﬀers excellent computing facilitities, running under Linux, and including data reduction programmes such as IRAF. Researchers of the Stellar Physics Department also have free access to the computer cluster (http://wave.asu.cas.cz/ocas/). The salary will be based on the standard domestic scale. The starting date is expected to be earliest in Summer 2011 (subject to negotiation) but not later than January 2012. The position is initially for one year but extension will be possible upon satisfactory scientiﬁc results and publication output until at least the end of 2013. Applicants should send their curriculum vitae, including a list of publications and a summary of the research interests and plans, and arrange to have two letters of recommendation sent to the director of the Institute at the following address: Astronomical Institute of the ASCR, v.v.i. Att. Prof. Petr Heinzel, director Fricova 298 CZ-251 65 Ondrejov Czech Republic [email protected] The closing date for applications is 11th March 2011. For informal inquiries please feel free to contact Dr. Michaela Kraus ([email protected]). Webpage of announcement: http://www.asu.cas.cz/news/271 post-doctoral-position-in-b-e-star-research/

4.12. Hα Spectroscopy and V Variations of Be Star 28 Tauri (Pleione) Ernst Pollmann Emil-Nolde-Straße 12, 51375 Leverkusen, Germany email: [email protected] Received: 2010 November 26; Accepted: 2011 June 8

Building on the review article by Hassforther (2008) on the same subject, with this contribution I would like to show the correlation between V brightness and the Hα equivalent width (EW). As a member of the Pleiades cluster the spectroscopic binary Be star (spectral type B8e) 28 Tau is well known as a shell star with photometric and spectroscopic long-term variations and cyclic changes in its spectrum from a Be phase to a Be-shell phase (Fig. 1) since the 19th century. Since 1938, an alternation of Be-shell and Be phases has been reported with a 35–36 years cycle.

2012, Be Star Newsletter, 40 − 45 Figure 1. High-resolution grating spectrum of 28 Tau (2009/11/19) in its current Be-shell phase.

The observed changes of the spectral characteristics from a Be phase to a Be- shell phase (and back) with this period is, because the disk “for some reason” (probably perturbation by the companion star at periastron) is not in the equatorial plane but slanted to the equator and precesses around the central star. This is manifested as variations of the Hα line profile (Hummel 1998). Currently the last Be-phase > Be-shell-phase observations (especially during the period November 2005 to April 2007) are interpreted as follows: every 35–36 years the spectroscopic companion star at periastron produces a mass loss from the primary star. As a result, a new disc is formed in the equatorial plane. During this process the old disc is already out of this equatorial plane, due to the precession caused by the companion. This process is then directly manifested in Hα emissivity. The historical V light curve in Fig. 2, from the database by S. Otero (private communication 2009), published V data by Tanaka et al. (2007), and other sources (see legend in this figure), and the Hα EW long-term monitoring by professional and amateur observations in Fig. 3 (sources: see legend in this figure) made it possible to look for any correlation between V and EW. Because 74 simultaneous measurements of V and EW could be identified from all measurements, the correlation in Fig. 4 between Hα EW and overall brightness shows, to what extent the brightness increase of V is influenced by the brightness of the disc (determined by the Hα EW). The EW error bars in Fig. 4 correspond to the attainable accuracy of one observation in one night (±1 A).˚ The error bars in V correspond to an assumed average measurement accuracy of all involved observers (±0.03 mag). If the variations in brightness are mainly caused by variations in the brightness of the disc, then at EW = 0 the (photospheric) V brightness (strictly taken only at Hα wavelength 6563 A)˚ would be approximately 5.4 mag. In other words, each increase above this value would therefore be attributable to Be star disc emissivity.

2012, Be Star Newsletter, 40 − 46 Figure 2. Historical V light curve from various sources.

Figure 3. Time behaviour of the Hα equivalent width from professional and amateur observations.

2012, Be Star Newsletter, 40 − 47 Figure 4. Correlation of the Hα equivalent width versus V brightness from 74 simultaneous measurements.

A large number of amateur spectra by J. Guarro, CH. Buil, and B. Mauclaire are available to continue investigations in this area. They can be found in the BeSS database for Be stars of the observatory Paris Meudon (http://basebe.obspm.fr/basebe/). References Hassforther, B. 2008, BAV-Rundbrief (ISSN 0405-5497), 1, 35 Hummel, W. 1998, A&A, 330, 243 Tanaka, K. et al. 2007, PASJ, 59, L35-L39

4.13. Ca II K line proﬁle in the latest Be-epoch of Pleione Jun-ichi Katahira1, Kazutoshi Inoue2, Yoshihito Kawabata3, and Tetuya Kawabata4 1 Nakanoshima Science Institute, Osaka Foundation for the Progress of Science, Nakanoshima, Kitaku, Osaka 530-0005, Japan email: [email protected] 2 1-11, Kibogaoka 2, Toyono-cho, Toyono, Osaka 563-0214, Japan 3 Kyoto Seibo Gakuin Junior High School / High School, Fukakusa, Fusimi-ku, Kyoto 612-0878, Japan 4 Shinonokaze 3-252, Midori-ku, Nagoya, Aichi 458-0015, Japan Recieved: 1 April 2011; Accepted: 28 August 2011 Pleione (28 Tau, HD23862; B8IVe) is a well-known classical Be star in the Pleiades cluster, and has a high rotational velocity v sin i of almost 300 km s−1 (Chauville et al. 2001). During the past 80 years, this star has shown three times the successive formation of the equatorial circumstellar disk with a period of about 34 years, which started at 1938, 1972 and 2005, respectively (Hirata 1995, Tanaka et al. 2007). After the beginning of circumstellar disk formation, Pleione usually develops a Be-shell phase and a subsequent Be phase.

2012, Be Star Newsletter, 40 − 48 Gulliver (1977) found a wide and shallow profile of Ca II K line just before the beginning of Be-shell phase at 1972, and concluded that the appearance of a weak and broad component of Ca II K line is a precursor of new disk formation. In 2002 March we started on monitoring the Ca II K line to find a new disk formation at the Bisei Astronomical Observatory (BAO). Before finding a wide and shallow profile of Ca II K line at 2005 December (Tanaka et al. 2007), we have observed the Ca II K line of Pleione three times, when we had the similar feature as Gulliver (1977) observed at the previous Be phase in 1969–1970, and recognized no existence of the wide and shallow feature. However, from the obtained three profiles we now suppose that the Ca II K line had an emission component in the late epoch of the previous Be phase. In the following we report the profiles of the Ca II K line in the late Be epoch of Pleione, together with the high- dispersion observations, and discuss a variation of the profile in 2000–2004. The observations at the BAO were carried out with a mid-dispersion spectrograph of spectral resolution power of about 10000, attached to the folded Cassegrain focus of 101cm reflector. The detector was a LN2-cooled AstroCam4200 CCD, by which a 400 A˚ region was obtained. We got two frames of the Ca II K line spectral region with the exposure time of 600 sec on 2002 March 19, three frames with the 600s-exposure on 2003 November 16, and three frames with the 1200s-exposure on 2004 December 21, respectively. The obtained Ca II K profiles are plotted in figure 1a. The S/N ratio of the profiles is estimated to be in 280–380. For the profiles in the previous years, the high-dispersion profiles of the Ca II K line in 2000–2002 are obtained from the ELODIE library v3.1 (Prugniel et al. 2007). For each observation epoch in the database the original profiles are processed by a simple averaging method, and the resultant mean profile is renormalized as to the modified continuum level of a straight line to obtain the final profile of Ca II K line. In addition, the profile on 2003 September 27 is taken from the SMOKA database (Baba et al. 2002), which was observed by the High Dispersion Echelle spectrograph (HIDES). These profiles are drawn in Fig. 1b, where we tentatively add a synthetic photospheric spectrum to see the photospheric and circumstellar contributions. According to the stellar fundamental parameters of Chauville et al. (2001), the synthetic one is simulated by the ’SPTOOL’ soft based on the ATLAS9 (released by Y. Takeda, National Astronomical Observatory of Japan), and that is renormalized at the intensity-levels of the far wings of the Ca II K line to match the profiles presented here. In Fig. 1 we find the interstellar component of the Ca II K line at a glance, and recognize the existence of the swells of profile on both sides of the interstellar component (indicated by upward arrows in the figures). The synthetic photospheric spectrum suggests that the swells of Ca II K lines mostly fill the photospheric component, and that the photospheric component is traced only at a 3930.5 A˚ region of the wing. Especially in 2000, a structure of the swells above the photosperic component has a marked characteristic, i.e., the blueward swell is very stronger than the redward one. So, a similar profile among the Fe II emission lines (V R) is easily found in the ELODIE spectra in 2000. Moreover, it is noted that the Na I D resonance lines have almost same emission features as the Ca II K line in spite of the severe contamination of the atmospheric lines. These may show a reality of the swells of Ca II K line. To see an overall variation of Ca II K profile in 2000–2004, we make a convolution of high- dispersion profiles plotted in Fig. 1b, with a Gaussian function estimated from a comparison spectrum of BAO. The resultant profiles are plotted in Fig. 2a together with the BAO profiles. The convoluted synthetic spectrum is also added. We notice that there is some tendency for the ratio of the blueward to redward swell intensities to vary between 2000 and 2004, i.e., the blueward swell intensity is stronger than the redward swell intensity in 2000, and the intensities of two swells are nearly equal in 2004.

2012, Be Star Newsletter, 40 − 49 Figure 1. (a)Ca II K line proﬁles observed with the mid-dispersion spectrograph at the Bisei Astro- nomical Observatory (BAO) in 2002 March–2004 December. (b)Ca II K line proﬁles from high-dispersion in 2000 January–2003 September. The data are taken from ELODIE library v3.1 (Prugniel et al. 2007) in 2000–2002, and SMOKA database (Baba et al. 2002) in 2003. The swells on both sides of interstellar component are indicated by upward arrows.

Since such a tendency for the two swell intensities of Ca II K profile is similar to the V/R variation of the double peak emission intensities of the Fe II lines in 2000–2004, we compare a variation of intensity-ratio of two swells of Ca II K with the V/R variation of Fe II lines. In Fig. 2b the values of intensity-ratio for two swells of Ca II K line are plotted over the V/R variation of strong 8 Fe II emission lines. The intensity ratios for the swells of Ca II K are directly read out from Fig. 2a without a correction of the photospheric component. The data for the Fe II emission intensities are obtained from Iliev (2000), Saad et al. (2006), Rivinius et al. (2006), the archived data referred in Fig. 1b, and our observations at the BAO. As the time variation for the ratio of the swell intensities of Ca II K line in figure 2b is alike to the V/R variation of the Fe II emission lines, we think that the swells on both sides of the Ca II K interstellar component are composed of the double emission components. If such an imagination is real, the observations plotted in Fig. 1 firstly show an appearance of the emission component of Ca II K in the late Be epoch. And, an emission component of Ca II K line may be formed in the circumstellar disk together with the emission component of Fe II lines.

2012, Be Star Newsletter, 40 − 50 Figure 2. (a) Ca II K line proﬁles from the convoluted high-dispersion (red lines) and mid-dispersion in 2000–2004. Upward arrows show the swells on the both sides of the interstellar component. (b) V/R variation of strong Fe II emission lines and the change of the intensity ratio of Ca II K swell-components. The data sources are given in the text.

We discussed a reliability for an existence of the Ca II K emission in the late Be phase from the profiles plotted in Fig. 1. As the number of the reported profiles is small, a confirmation of the emission component may be not sufficient. Perhaps, because of its weakness of an emission intensity, the emission may be overlooked until now. We earnestly propose to research the spectral data-archive observed in the previous Be phase. References Baba, H., Yasuda, N., Ichikawa, S., et al. 2002, eds. D. A. Bohlender, D. Durand, & T. H. Handley, ASP Conference Series, Vol.281, 298 Chauville, J., Zorec, J., Ballereau, D, et al. 2001, A&A, 378, 861 Gulliver, A.F. 1977, ApJS, 35, 441 Hirata, R. 1995, PASJ, 47, 195 Iliev, L. 2000, eds. M. A. Smith, H. F. Henrichs, & J. Fabregat, ASP Conference Series, Vol.214, 566 Prugniel, P., Soubiran, C., Koleva, M., & Le Borgne, D. 2007, arXiv:astrp-ph/0703658V1 Rivinius, Th.,Stefl,ˇ S., & Baade, D. 2006, A&A, 459, 137 Saad, S. M., Kubát,J., Korćková,D., et al. 2006, A&A, 450, 427 Tanaka, K., Sadakane, K., Narusawa, S., et al. 2007, PASJ, 59, L35

2012, Be Star Newsletter, 40 − 51 4.14. Workshop: “Circumstellar Dynamics at High Resolution” (First Announcement) Alex Carciofi Instituto de Astronomia, Geof´ısicae CiênciasAtmosféricas,Universidade de SãoPaulo, Rua do Matão1226, Cidade Universitária,05508-900, SãoPaulo, SP, BRAZIL email: [email protected] This is the first announcement of a conference on “Circumstellar Dynamics at High Reso- lution” to be held February 27 to March 02, 2012. The venue of the meeting will be in Foz do Igua¸cu,Brazil. The Workshop is sponsored by ESO and the University of SãoPaulo. More detailed information is available on our web page: http://www.eso.org/sci/meetings/2012/csdyn.html or by email to [email protected]. We encourage you to circulate the announcement among your colleagues. On behalf of the organizers, Alex Carciofi

*** SCOPE *** The dynamics of circumstellar (CS) envelopes is an active research frontier that has ben- efited greatly from the advent of high-resolution observational techniques in the spectral, spatial and temporal domains. The observational discoveries and theoretical results emerging from this field have broad implications for many astrophysical topics, ranging from cosmology (via a better understanding of the progenitors of GRBs, for instance), to star and planet formation (through a better description of CS disk dynamics in which viscosity plays a key role). The diverse and complex CS environments revealed by these observational techniques are particularly evident near hot high-mass stars, where stellar radiation plays a large if not crucial role in continuously shaping the immediate environment. High-resolution observations (spatial, spectral, and temporal) have provided important information in several frontline research topics. For example, many hot stars have been shown to be very rapidly rotating, in a regime where geometric deformation and gravity darkening become important. CS structures have not only been resolved spatially, but have been followed over characteristic variation timescales. This dynamical evolution has been modeled for disks and winds: we are now directly observing and measuring the consequence of the physical mechanisms operating within the CS environments. As a result, current observing facilities have allowed the field to progress from a static picture of the CS environment towards understanding its dynamics and concomitant impact on the evolution of the central star. This workshop aims at bringing together the active community of hot stellar astrophysics, both theoreticians and observers, along the common topic of what can be learned from high resolution observations.

2012, Be Star Newsletter, 40 − 52 *** PROGRAM *** Oral sessions during the meeting will be held on:

1. Circumstellar Disks & Outﬂows: Theory 2. Circumstellar Disks & Outﬂows: Observations 3. Delta Sco and Be stars as laboratories for CS disk physics 4. Dynamics of Circumstellar Material and tidal interactions in hot binaries 5. Massive star formation out of a dynamic environment 6. Magnetospheres of Hot Stars

*** VENUE *** The workshop will take place in Foz do Igua¸cu,Brazil, close to the magnificent Igua¸cu Waterfalls, a network of 275 waterfalls in the Igua¸cuRiver that lies in the border of Brazil and Argentina. The site was designated World Heritage by UNESCO. Tourist attractions include visits to both the Brazilian and Argentinian sides of the Falls, natural parks, and the dam of the Itaipu Hydroeletric Facility. In 1994, the American Society of Civil Engineers elected the Itaipu Dam as one of the seven modern Wonders of the World. The Meeting will take place in the Rafain Hotel and Convention Centers (http://www.rafainpalace.com.br/v2/home/). Special rates are available for the period of the conference. Hotel costs are 274 BRL (170 USD) for single occupancy and 171 BRL (106 USD) per person for double occupancy. Those rates include full board (breakfast, morning coffebreak, lunch, afternoon coffebreak and dinner). IMPORTANT NOTE: all participants are encouraged to register in this hotel for two reasons. First, those low rates will only be secured if a minimum of 50 rooms is booked. Second, the hotel is far from the city (10km) and there are no restaurants nearby.

*** PRE-REGISTRATION *** If you intend to participate in the workshop please ﬁll in the pre-registration form in our web page. This is not a formal registration, and requires no commitment from you. Our goal is to have an idea about the number of participants for organization purposes.

*** PROCEEDINGS *** We will have online conference proceedings, whether these will be published in print depends on funding decisions made towards the end of 2011 only.

*** FINANCIAL MATTERS *** The workshop fee will be 200 USD. We will have some limited ﬁnancial support for students and young researchers. Money will be requested for the Brazilian students that do not have research contingency funds.

*** DEADLINES *** Requests for ﬁnancial support must be submitted by Nov. 1st at the latest, together with the abstract of the intended contribution. The deadline for the ﬁnal registration and abstracts is Dec. 17th.

2012, Be Star Newsletter, 40 − 53 *** CONTACT *** Website: http://www.eso.org/sci/meetings/2012/csdyn.html Mail: [email protected] SOC: A. C. Carciofi (co-chair), D. Baade, J. E. Bjorkman, A. Damineli, W. Dent, A. Domi- ciano de Souza, Th. Rivinius (co-chair), S. Stefl,ˇ J. Vink, G. Wade LOC: A. Carciofi (chair), A. Damineli, M. Borges, M. Teodoro, C. Barbosa, D. M. Faes, M.E. Gomez, Th. Rivinius, C. Martayan

4.15. Workshop: “Circumstellar Dynamics at High Resolution” (Last Announcement) Alex Carciofi Instituto de Astronomia, Geof´ısicae CiênciasAtmosféricas,Universidade de SãoPaulo, Rua do Matão1226, Cidade Universitária,05508-900, SãoPaulo, SP, BRAZIL email: [email protected] Received: 19 December 2011

Last announcement:

ESO Workshop: Circumstellar Dynamics at High Resolution Foz do Igua¸cu,Brazil, February 27 -- March 02, 2012 http://www.eso.org/sci/meetings/2012/csdyn.html Info: [email protected]

The deadline for late registration is approaching fast: Jan. 13th.

Financial support Support is available to partially cover hotel expenses for a few students and post-docs. Applications can be submitted by via the registration form. Sessions will be held on:

Conﬁrmed invited speakers E. Alecian (Observatoire de Paris, France) J. Bjorkman (Univ. of Toledo, US) D. Cohen (Swarthmore College)

2012, Be Star Newsletter, 40 − 54 W. Dent (ALMA) W.-J. de Wit (ESO) J. Groh (Max-Planck-Institute for Radioastronomy, Germany) C. Jones (Univ. of Western Ontario, Canada) M. Krumholz (Univ. of California, US) A. M. Magalh˜aes (Univ. of So Paulo, Brazil) F. Millour (Univ. of Nice, France) A. Miroshnichenko (Univ. of North Carolina at Greensboro, US) A. Okazaki (Hokkai-Gakuen Univ., Japan) R. Oudmaijer (Univ. of Leeds, UK) S. Owocki (Univ. of Delaware, US) R. Townsend (Univ. of Wisconsin, US) A. ud-Doula (Penn State W. Scranton, US)

SOC D. Baade, A. C. Carcioﬁ (co-chair), J. E. Bjorkman, A. Daminelli, W. Dent, A. Domi- ciano de Souza, Th. Rivinius (co-chair), S. Steﬂ,ˇ J. Vink, G. Wade

Venue The workshop will take place in Foz do Igua¸cu,Brazil, close to the magniﬁcent Igua¸cu Waterfalls, a network of 275 waterfalls in the Igua¸cuRiver that lies in the border of Brazil and Argentina.

Tours Two visits to the waterfalls are planned during the workshop. For more details, see http://www.eso.org/sci/meetings/2012/csdyn/local.html#par title.

We look forward to see you in Brazil next February!

Alex Carcioﬁ, for the SOC

4.16. First Announcement: 11th Hvar Astrophysical Colloquium

Domagoj Ruzdjak Hvar Observatory, Faculty of Geodesy, Kaciceva 26, Zagreb, Croatia, 10000 email: [email protected] Received: 29 February 2012

Dear Colleagues, At the occasion of the 40th anniversary of Hvar Observatory we are organizing 11th Hvar Astrophysical Colloquium “The Most Mysterious Binaries: Signiﬁcance for Astrophysics”, Hvar, Croatia, July 2–6, 2012 (http://www.geof.unizg.hr/oh/meetings/). Yours sincerely, Domagoj Ruzdjak

2012, Be Star Newsletter, 40 − 55 4.17. Long bright outburst of the Be star µ Cen Sebasti´anA. Otero American Association of Variable Star Observers (AAVSO) email: [email protected] Received: 2012 May 14; Accepted: 2012 May 15

Mu Centauri (B2IV-Ve) is one of the brightest Southern Be stars. Its extreme V magnitudes are 2.85 and 3.55. Its quiescent magnitude ranges from V = 3.40 to 3.55. The brightest outburst peaked around March 23, 1963 and was observed by Johnson (Feinstein 1968). The outburst duration can’t be constrained due to lack of continuous coverage but that time the star remained bright during at least 2 years. After that outburst the star was usually observed at its quiescent state and found to be a multiperiodic non-radially pulsating star (Rivinius et al. 2001). In 1989, Cuypers et al. made an intensive photometric campaign on the star and found a period of 2.1017 d with a double-wave light curve superposed on the irregular brightness variations. Hipparcos observations do not show that period but do show small outbursts with a total amplitude of 0.1 magnitude. The historical light curve with data compiled from the literature can be seen in Fig. 1.

Figure 1. Visual light curve of mu Centauri spanning from 1957 to 2012.

The star has been observed visually for the last 14 years and only 5 outbursts brighter than V = 3.3 were recorded over that period (Fig. 2), the three brightest ones having occurred after 2006 (Otero 2006, 2007, 2009). The 2006 and 2007 events lasted more than 100 days and reached V = 3.1 showing multiple peaks before the return to quiescence. The 2009 brightening only lasted for 12 days and reached V = 3.2. A new outburst is currently under way and it seems to belong to the long-lasting type since the star has been bright for a month and still with a rising trend.

2012, Be Star Newsletter, 40 − 56 Figure 2. Visual light curve of mu Centauri from 1998 to 2012.

The most recent visual observations by S. Otero (Fig. 3) are: 2012, Mar 30.131, V = 3.51 2012, Apr 16.304, V = 3.20 2012, Apr 18.047, V = 3.19 2012, Apr 21.293, V = 3.19 2012, Apr 30.955, V = 3.17 2012, May 12.032, V = 3.12 2012, May 12.978, V = 3.11 2012, May 15.063, V = 3.09

Figure 3. The last two years of mu Centauri showing its quiescent state and the current outburst.

2012, Be Star Newsletter, 40 − 57 Spectroscopic observations during this event are encouraged. References Cuypers, J., Balona, L. A., Marang, F. 1989, A&AS, 81, 151 Feinstein, A. 1968, Zeitschrift f¨urAstrophysik, 68, 29 Otero, S. 2006, The Be Star Newsletter, No. 38 Otero, S. 2007, The Be Star Newsletter, No. 39 Otero, S. 2009, The Be Star Newsletter, No. 40 Perryman, M. A. C., et al. 1997, A&A, 323, 4 Rivinius, Th. et al. 2001, The Journal of Astronomical Data, Vol. 7, Number 5

2012, Be Star Newsletter, 40 − 58 5. ABSTRACTS

Cyclic variability of the circumstellar disk of the Be star zeta Tau - I. Long-term monitoring observations

S. Steflˇ 1, Th. Rivinius1, A. C. Carciofi2, J.-B. Le Bouquin1, D. Baade3, K. S. Bjorkman4, E. Hesselbach4, C. A. Hummel3, A. T. Okazaki5, E. Pollmann6, F. Rantakyrö7, and J. P. Wisniewski8 1 European Organisation for Astronomical Research in the Southern Hemisphere, Casilla 19001, Santiago 19, Chile 2 Instituto de Astronomia, Geof´ısicae CiênciasAtmosféricas,Universidade de SãoPaulo, Rua do Matão 1226, Cidade Universitária,SãoPaulo, SP 05508-900, Brazil 3 European Organisation for Astronomical Research in the Southern Hemisphere, Karl-Schwarzschild-Str. 2, 85748 Garching bei München, Germany 4 University of Toledo, Department of Physics & Astronomy, MS111 2801 W. Bancroft Street Toledo, OH 43606, USA 5 Faculty of Engineering, Hokkai-Gakuen University, Toyohira-ku, Sapporo 062-8605, Japan 6 Emil-Nolde-Str.12, 51375 Leverkusen, Germany 7 Gemini Observatory, Southern Operations Center, c/o AURA, Casilla 603, La Serena, Chile 8 NSF Astronomy & Astrophysics Postdoctoral Fellow, Department of Astronomy, University of Washing- ton, Box 351580, Seattle, WA 98195, USA

Context. Emission lines formed in decretion disks of Be stars often undergo long-term cyclic variations, especially in the violet-to-red (V/R) ratio of their primary components. The underlying structural and dynamical variations of the disks are only partly understood. From observations of the bright Be-shell star ζ Tau, the possibly broadest and longest data set illustrating the prototype of this behaviour was compiled from our own and archival observations. It comprises optical and infrared spectra, broad-band polarimetry, and interferometric observations. Aims. The dense, long-time monitoring permits a better separation of repetitive and ephemeral variations. The broad wavelength coverage includes lines formed under different physical conditions, i.e. different locations in the disk, so that the dynamics can be probed throughout much of the disk. Polarimetry and interferometry constrain the spatial structure. All together, the objective is a better understand the dynamics and life cycle of decretion disks. Methods. Standard methods of data acquisition, reduction, and analysis were applied. Results. From 3 V/R cycles between 1997 and 2008, a mean cycle length in Hα of 1400–1430 days was derived. After each minimum in V/R, the shell absorption weakens and splits into two components, leading to 3 emission peaks. This phase may make the strongest contribution to the variability in cycle length. There is no obvious connection between the V/R cycle and the 133-day orbital period of the not otherwise detected companion. V/R curves of different lines are shifted in phase. Lines formed on average closer to the central star are ahead of the others. The shell absorption lines fall into 2 categories differing in line width, ionization/excitation potential, and variability of the equivalent width. They seem to form in separate regions of the disk, probably crossing the line of sight at different times. The interferometry has resolved the continuum and the line emission in Brγ and He I 2.06. The phasing of the Brγ emission shows that the photocenter of the line-emitting region lies within the plane of the disk but is offset from the continuum source. The plane of the disk is constant throughout the observed V/R cycles. The observations lay the foundation for

2012, Be Star Newsletter, 40 − 59 the fully self-consistent, one-armed, disk-oscillation model developed in Paper II. A&A 2009, 504, 929

Variability of Be Stars in Southern Open Clusters M. Virginia McSwain1, Wenjin Huang2, and Douglas R. Gies3 1 Department of Physics, Lehigh University, 16 Memorial Drive East, Bethlehem, PA 18015 2 Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195-1580 3 Center for High Angular Resolution Astronomy, Department of Physics and Astronomy, Georgia State University, P.O. Box 4106, Atlanta, GA 30302-4106

We recently discovered a large number of highly active Be stars in the open cluster NGC 3766, making it an excellent location to study the formation mechanism of Be star disks. To explore whether similar disk appearances and/or disappearances are common among the Be stars in other open clusters, we present here multiple epochs of Hα spectroscopy for 296 stars in eight open clusters. We identify 12 new transient Be stars and confirm 17 additional Be stars with relatively stable disks. By comparing the Hα equivalent widths to the photometric y–Hα colors, we present a method to estimate the strength of the Hα emission when spectroscopy is not available. For a subset of 128 stars in four open clusters, we also use blue optical spectroscopy and available Strömgrenphotometry to measure their projected rotational velocities, effective temperatures, and polar surface gravities. We combine our Be star detections from these four clusters to investigate physical differences between the transient Be stars, stable Be stars, and normal B-type stars with no line emission. Both types of Be stars are faster rotating populations than normal B-type stars, and we find no significant physical differences between the transient and stable Be stars in our sample. ApJ, 2009, 700, 121

A slitless spectroscopic survey for Hα emission-line objects in SMC clusters C. Martayan1,2, D. Baade3 and J. Fabregat4 1 European Organisation for Astronomical Research in the Southern Hemisphere, Alonso de Cordova 3107, Vitacura, Casilla 19001, Santiago 19, Chile 2 GEPI, Observatoire de Paris, CNRS, UniversitéParis Diderot, 5 place Jules Janssen, 92195 Meudon Cedex, France 3 European Organisation for Astronomical Research in the Southern Hemisphere, Karl-Schwarzschild-Str. 2, 85748 Garching b. München, Germany 4 Institute Two and Address Observatorio Astronómicode Valencia, edifici Instituts d’investigació,Poligon la Coma, 46980 Paterna Valencia, Spain

Context. A fair fraction of all single early-type stars display emission lines well before the supergiant phase. Very rapid rotation is necessary for such stars to form rotationally supported decretion disks. But it is unknown whether and which other parameters may be important. Aims. This paper checks on the roles of metallicity and evolutionary age in the appearance of the so-called Be phenomenon. Methods. Slitless CCD spectra were obtained covering the bulk (about 3 square degrees) of

2012, Be Star Newsletter, 40 − 60 the Small Magellanic Cloud. For Hα line emission twice as strong as the ambient continuum, the survey is complete to spectral type B2/B3 on the main sequence. About 8,120 spectra of 4,437 stars were searched for emission lines in 84 open clusters. 370 emission-line stars were found, among them at least 231 near the main sequence. For 176 of them, photometry could be found in the OGLE database. For comparison with a higher-metallicity environment, the Galactic sample of the photometric Hα survey by McSwain & Gies (2005) was used. Results. Among early spectral sub-types, Be stars are more frequent by a factor ∼3–5 in the SMC than in the Galaxy. The distribution with spectral type is similar in both galaxies, i.e. not strongly dependent on metallicity. The fraction of Be stars does not seem to vary with local star density. The Be phenomenon mainly sets in towards the end of the main- sequence evolution (this trend may be more pronounced in the SMC); but some Be stars already form with Be-star characteristics. In small sub-samples (such as single clusters), even if they appear identical, the fraction of emission lines stars can deviate drastically from the mean. Conclusions. In all probability, the fractional critical angular rotation rate, Ω , is one of Ωc the main parameters governing the occurrence of the Be phenomenon. If the Be character is only acquired during the course of evolution, the key circumstance is the evolution of Ω , Ωc which not only is dependent on metallicity but differently so for different mass ranges. As the result, even if the Be phenomenon is basically single-parametric (namely Ω ), it takes Ωc on a complex multi-parametric appearance. The large cluster-to-cluster differences, which seem stronger than all other variations, serve as a caveat that this big picture may undergo significant second-order modulations (pulsations, initial angular momentum, etc). A&A, 2010, 509, 11

Using Optical/Near-IR Interferometric Polarimetry to Place Constraints on the Disks Surrounding Be Stars F. E. Mackay1, N. M. Elias II2,3,4, C. E. Jones1, and T. A. A. Sigut1 1 Department of Physics and Astronomy; The University of Western Ontario; London, Ontario N6A 3K7; Canada 2 Zentrum fürAstronomie der UniversitätHeidelberg Landessternwarte; Königstuhl12; 69117 Heidelberg; Germany 3 Max-Planck-Institut fürAstronomie; Königstuhl17; 69117 Heidelberg; Germany 4 National Radio Astronomy Observatory; Array Operations Center; P.O. Box O; 1003 Lopezville Road; Socorro, NM 87801-0387; USA

We present predictions for the normalized Stokes visibilities of a Be star disk, as would be measured by an interferometric polarimeter. Using both a simple geometric model for the disk as well as a more complex radiative transfer model, we investigate, in detail, the effect of each of the model parameters on the resultant normalized Stokes visibilities. We find normalized visibility amplitudes for the total star and disk system of ∼10−2–10−3 at shorter baselines, and ∼10−3–10−4 at longer baselines, requiring, at small and moderate baselines, an accuracy for interferometric polarization observations better than ∼10−3–10−4, including all random and systematic errors. Provided this level of accuracy is attainable, we find that the Stokes Q visibility may be important both for the removal of model degeneracies present when considering the intensity alone, as well as for providing an estimate of the inclination angle of the disk. ApJ, 2009, 704, 591

2012, Be Star Newsletter, 40 − 61 VLTI/MIDI observations of 7 classical Be stars

A. Meilland1, Ph. Stee2, O. Chesneau2, and C. Jones3 1 Max Planck Institut fur Radioastronomie, Auf dem Hugel 69, 53121 Bonn, Germany 2 UMR 6525 CNRS FIZEAU UNS, OCA, CNRS, Campus Valrose, 06108 Nice Cedex 2, France 3 Physics and Astronomy Department, The University of Western Ontario, London, N6A 3K7, Ontario, Canada

Context. Classical Be stars are hot non-supergiant stars surrounded by a gaseous circumstellar envelope that is responsible for the observed IR-excess and emission lines. The origin of this envelope, its geometry, and kinematics have been debated for some time. Aims. We measured the mid-infrared extension of the gaseous disk surrounding seven of the closest Be stars in order to constrain the geometry of their circumstellar environments and to try to infer physical parameters characterizing these disks. Methods. Long baseline interferometry is the only technique that enables spatial resolution of the circumstellar environment of classical Be stars.We used the VLTI/MIDI instrument with baselines up to 130 m to obtain an angular resolution of about 15 mas in the N band and compared our results with previous K band measurements obtained with the VLTI/AMBER instrument and/or the CHARA interferometer. Results. We obtained one calibrated visibility measurement for each of the four stars, p Car, ζ Tau, κ CMa, and α Col, two for δ Cen and β CMi, and three for α Ara. Almost all targets remain unresolved even with the largest VLTI baseline of 130 m, evidence that their circumstellar disk extension is less than 10 mas. The only exception is α Ara, which is clearly resolved and well-ﬁtted by an elliptical envelope with a major axis a = 5.8 ± 0.8 mas and an axis ratio a/b = 2.4 ± 1 at 8 µm. This extension is similar to the size and ﬂattening measured with the VLTI/AMBER instrument in the K band at 2 µm. Conclusions. The size of the circumstellar envelopes for these classical Be stars does not seem to vary strongly on the observed wavelength between 8 and 12 µm. Moreover, the size and shape of α Ara’s disk is almost identical at 2, 8, and 12 µm. We expected that longer wavelengths probe cooler regions and correspondingly larger envelopes, but this is clearly not the case from these measurements. For α Ara this could come from to disk truncation by a small companion; however, other explanations are needed for the other targets. A&A, 2009, 505, 687

S 235 B explained: an accreting Herbig Be star surrounded by reﬂection nebulosity

P. Boley1, A. Sobolev1, V. Krushinsky1, R. van Boekel2, Th. Henning2, A. Moiseev3, and M. Yushkin3 1 Ural State University, 620083 Ekaterinburg, Russia 2 Max-Planck-Institut f¨urAstronomie, D-69117 Heidelberg, Germany 3 Special Astrophysical Observatory of the RAS, 357147 Nizhnii Arkhyz, Russia

The intent of this study is to determine the nature of the star and associated nebulosity S 235 B, which are located in a region of active star formation still heavily obscured by the parent molecular cloud. Low-resolution (R = 400) long-slit spectra of the star and nebulosity, and medium- (R = 1800) and high-resolution (R = 60 000) spectra of the central star are presented along with the results of Fabry-Perot interferometric imaging

2012, Be Star Newsletter, 40 − 62 of the entire region. Based on the long-slit and Fabry-Perot observations, the nebulosity appears to be entirely reflective in nature, with the stellar component S 235 B? providing most of the illuminating flux. The stellar source itself is classified here as a B1V star, with emission line profiles indicative of an accretion disk. S 235 B? thus belongs to the relatively rare class of early-type Herbig Be stars. Based on the intensity of the reflected component, it is concluded that the accretion disk must be viewed nearly edge-on. Estimates of the accretion rate of S 235 B? from the width of the Hα profile at 10% of maximum intensity, a method which has been used lately for T Tauri stars and Brown Dwarfs, appear to be inconsistent with the mass outflow rate and accretion rate implied from previous infrared observations by Felli et al. (2006), suggesting this empirical law does not extend to higher masses. 2009, MNRAS, 399, 778

On the presence and absence of disks around O-type stars Jorick S. Vink1, B. Davies2,3, T. J. Harries4, R. D. Oudmaijer2, and N. R. Walborn5 1 Armagh Observatory, UK 2 Leeds University, UK 3 RIT, USA 4 University of Exeter, UK 5 STSCI, USA

As the favoured progenitors of long-duration gamma-ray bursts, massive stars may represent our best signposts of individual objects in the early Universe, but special conditions seem required to make these bursters. These are thought to originate from the progenitor’s rapid rotation and associated asymmetry. To obtain empirical constraints on the interplay between stellar rotation and wind asymmetry, we perform linear Hα spectropolarimetry on a sample of 18 spectroscopically peculiar massive O stars, including OVz, Of?p, Oe, and Onfp stars, supplemented by an earlier sample of 20 O supergiants of Harries et al., yielding a total number of 38 O-type stars. Our study’s global aim is to characterize the differences between, and similarities amongst, different classes of peculiar O stars and to establish in how far they differ from garden-variety O stars. Our linear (Stokes QU) spectropolarimetry data should be regarded a geometric counterpart to (Stokes I) spectral classification, setting the stage for circular (Stokes V ) polarimetric searches for magnetic fields. Despite their rapid rotation (with v sin i up to ∼ 400 km s−1) most O-type stars are found to be spherically symmetric, but with notable exceptions amongst specific object classes. We divide the peculiar O stars into four distinct categories: Group I includes the suspected young zero-age main sequence OVz stars and related weak-winds objects, of which the magnetic star Theta 1 Ori C is the most famous member. These objects show no evidence for significant linear polarization. Group II includes the Of?p stars, in which one of its members, HD 191612, was also found to be magnetic. These objects show more linear polarization activity than those in group I. Group III includes the Oe stars, which have been suggested to be the more massive counterparts to classical Be stars, and Group IV concerns the Onfp stars. Objects from the latter two groups are on the high-end tail of the O star rotation distribution and have in the past been claimed to be embedded in disks. Here we report the detection of a classical depolarization “line effect” in the Oe star HD 45314, but the overall incidence of line effects amongst Oe stars is significantly lower (1 out of 6) than amongst Be stars. The chance that the Oe and Be datasets are drawn

2012, Be Star Newsletter, 40 − 63 from the same parent population is negligible (with 95% confidence). This implies there is as yet no evidence for a disk hypothesis in Oe stars, providing relevant constraints on the physical mechanism that is responsible for the Be phenomenon. Finally, we find that 3 out of 4 of the group IV Onfp stars show evidence for complex polarization effects which are likely related to rapid rotation, and we speculate on the evolutionary links to B[e] stars. A&A, 2009, 505, 743

Disk Loss and Disk Renewal Phases in Classical Be Stars I: Analysis of Long-Term Spectropolarimetric Data John P. Wisniewski1, Zachary H. Draper1, Karen S. Bjorkman2, Marilyn R. Meade3, Jon E. Bjorkman2, and Adam F. Kowalski1 1 University of Washington, Box 351580, Seattle, WA 98195 2 University of Toledo, Dept. of Physics and Astronomy, MS 113, Toledo, OH 43606 3 University of Wisconsin, 1150 University Ave, Madison, WI 53706

Classical Be stars are known to occasionally transition from having a gaseous circumstellar disk (“Be phase”) to a state in which all observational evidence for the presence of these disks disappears (“normal B-star phase”). We present one of the most comprehensive spectropolarimetric views to date of such a transition for two Be stars, π Aquarii and 60 Cygni. 60 Cyg’s disk loss episode was characterized by a generally monotonic decrease in emission strength over a time-scale of ∼1000 days from the maximum V -band polarization to the minimum Hα equivalent width, consistent with the viscous time-scale of the disk, assuming α ∼ 0.14. π Aqr’s disk loss was episodic in nature and occurred over a time-scale of ∼2440 days. An observed time lag between the behavior of the polarization and Hα in both stars indicates the disk clearing proceeded in an “inside-out” manner. We determine the position angle of the intrinsic polarization to be 166.7 ± 0.1◦ for π Aqr and 107.7 ± 0.4◦ for 60 Cyg, and model the wavelength dependence of the observed polarization during the quiescent diskless phase of each star to determine the interstellar polarization along the line of sight. Minor outbursts observed during the quiescent phase of each star shared similar lifetimes as those previously reported for µ Cen, suggesting that the outbursts represent the injection and subsequent viscous dissipation of individual blobs of material into the inner circumstellar environments of these stars. We also observe deviations from the mean intrinsic polarization position angle during polarization outbursts in each star, indicating deviations from axisymmetry. We propose that these deviations might be indicative of the injection (and subsequent circularization) of new blobs into the inner disk, either in the plane of the bulk of the disk material or in a slightly inclined (non-coplanar) orbit. ApJ, 2010, 709, 1306

Optical spectroscopy of 20 Be/X-ray Binaries in the Small Magellanic Cloud V. Antoniou1,2, D. Hatzidimitriou1, A. Zezas1,2,3, and P. Reig1,3 1 Physics Department, University of Crete, P.O. Box 2208, GR-710 03, Heraklion, Crete, Greece 2 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA 3 IESL, Foundation for Research and Technology, 71110 Heraklion, Crete, Greece

We present a large sample (20 in total) of optical spectra of Small Magellanic Cloud (SMC)

2012, Be Star Newsletter, 40 − 64 High-Mass X-ray Binaries obtained with the 2dF spectrograph at the Anglo-Australian Telescope. All of these sources are found to be Be/X-ray binaries (Be-XRBs), while for 5 sources we present original classifications. Several statistical tests on this expanded sample support previous findings for similar spectral-type distributions of Be-XRBs and Be field stars in the SMC, and of Be-XRBs in the Large Magellanic Cloud and the Milky Way, although this could be the result of small samples. On the other hand, we find that Be- XRBs follow a different distribution than Be stars in the Galaxy, also in agreement with previous studies. In addition, we find similar Be spectral type distributions between the Magellanic Clouds samples. These results reinforce the relation between the orbital period and the equivalent width of the Hα line that holds for Be-XRBs. SMC Be stars have larger Hα equivalent widths when compared to Be-XRBs, supporting the notion of circumstellar disk truncation by the compact object. ApJ, 2009, 707, 1080

A binary engine fuelling HD 87643’s complex circumstellar environment. Determined using AMBER/VLTI imaging F. Millour1, O. Chesneau2, M. Borges Fernandes2, A. Meilland1, G. Mars3, C. Benoist3, E. Thiébaut4, P. Stee2, K.-H. Hofmann1, F. Baron5, J. Young5, P. Bendjoya2, A. Carciofi6, A. Domiciano de Souza2, T. Driebe1, S. Jankov2, P. Kervella7, R. G. Petrov2, S. Robbe-Dubois2, F. Vakili2, L. B. F. M. Waters8, and G. Weigelt1 1 Max-Planck Institut fürRadioastronomie, Auf dem Hügel69, 53121 Bonn, Germany 2 UMR 6525 H. Fizeau, Univ. Nice Sophia Antipolis, CNRS, Observatoire de la Côted’Azur, 06108 Nice Cedex 2, France 3 UMR 6202 Cassiopée,Univ. Nice Sophia Antipolis, CNRS, Observatoire de la Côted’Azur, BP 4229, 06304 Nice, France 4 UMR 5574 CRAL, Univ. Lyon 1, Obs. Lyon, CNRS, 9 avenue Charles André,69561 Saint Genis Laval Cedex, France 5 Astrophysics Group, Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE, UK 6 Instituto de Astronomia, Geof´ısicae CiênciasAtmosféricas,Universidade de SãoPaulo, Rua do Matão 1226, Cidade Universitária,05508-900, SãoPaulo, SP, Brazil 7 LESIA, Observatoire de Paris, CNRS UMR 8109, UPMC, Univ. Paris Diderot, 5 place Jules Janssen, 92195 Meudon Cedex, France 8 Faculty of Science, Astronomical Institute “Anton Pannekoek”, Kruislaan 403, 1098 SJ Amsterdam, The Netherlands

Context. The star HD 87643, exhibiting the “B[e] phenomenon”, has one of the most extreme infrared excesses for this object class. It harbours a large amount of both hot and cold dust, and is surrounded by an extended reﬂection nebula. Aims. One of our major goals was to investigate the presence of a companion in HD 87643. In addition, the presence of close dusty material was tested through a combination of multiwavelength high spatial resolution observations. Methods. We observed HD 87643 with high spatial resolution techniques, using the near-IR AMBER/VLTI interferometer with baselines ranging from 60 m to 130 m and the mid-IR MIDI/VLTI interferometer with baselines ranging from 25 m to 65 m. These observations

2012, Be Star Newsletter, 40 − 65 are complemented by NACO/VLT adaptive- optics-corrected images in the K and L-bands, and ESO-2.2m optical Wide-Field Imager large-scale images in the B, V , and R-bands. Results. We report the direct detection of a companion to HD 87643 by means of image synthesis using the AMBER/VLTI instrument. The presence of the companion is con- ﬁrmed by the MIDI and NACO data, although with a lower conﬁdence. The companion is separated by ∼34 mas with a roughly north-south orientation. The period must be large (several tens of years) and hence the orbital parameters are not determined yet. Binarity with high eccentricity might be the key to interpreting the extreme characteristics of this system, namely a dusty circumstellar envelope around the primary, a compact dust nebulosity around the binary system, and a complex extended nebula suggesting past violent ejections. A&A, 2009, 507, 317

Formation and evolution of Ae and Be stars A. V. Tutukov and A. V. Fedorova 1 Institute of Astronomy, Russian Academy of Sciences, ul. Pyatnitskaya 48, Moscow, 109017, Russia

Several scenarios for the formation of accretion and decretion disks in single and binary Ae and Be stars are proposed. It is shown that, in order for a rapidly rotating main-sequence Be star to lose mass via a disk, the star’s rotation must be quasi-rigid-body. Estimates show that such rotation can be maintained by the star’s magnetic ﬁeld, which is probably a relict ﬁeld. The evolution of single Be main-sequence stars is numerically simulated allowing for mass loss via the stellar wind and rotational mass loss assuming rigid-body rotation. The stellar wind is the factor that determines the maximum mass of Be stars, which is close to 30 M . The evolution of Be stars in close binaries is analyzed in the approximation adopted in our scenario. Long gamma-ray bursts can be obtained as a result of the collapse of rapidly rotating oxygen-neon degenerate dwarfs — the accreting companions of Be stars — into neutron stars. ARep, 2007, 51, 847 (Original Russian Text c A.V. Tutukov, A.V. Fedorova, 2007, published in Astronomicheskii Zhurnal, 2007, Vol. 84, No. 10, pp. 937-953.)

γ Cassiopeiae: an X-ray Be star with personality R. Lopes de Oliveira1, M. A. Smith2, and C. Motch3 1 Instituto de Astronomia, Geof´ısicae CiênciasAtmosféricas,Universidade de SãoPaulo, R. do Matão1226, 05508-090 SãoPaulo, Brazil 2 Catholic University of America, 3700 San Martin Drive, Baltimore, MD 21218, USA 3 Universitéde Strasbourg, CNRS, UMR 7550, Observatoire Astronomique, 11 rue de l’Université,F-67000 Strasbourg, France

An exciting unsolved problem in the study of high energy processes of early type stars concerns the physical mechanism for producing X-rays near the Be star γ Cassiopeiae. By now we know that this source and several “γ Cas analogs” exhibit an unusual hard thermal X-ray spectrum, compared both to normal massive stars and the non-thermal emission of known Be/X-ray binaries. Also, its light curve is variable on almost all conceivable timescales. In this study we reanalyze a high dispersion spectrum obtained by Chandra in

2012, Be Star Newsletter, 40 − 66 2001 and combine it with the analysis of a new (2004) spectrum and light curve obtained by XMM-Newton. We find that both spectra can be fit well with 3–4 optically thin, thermal components consisting of a hot component having a temperature kTQ ∼ 12–14 keV, perhaps one with a value of ∼2.4 keV, and two with well defined values near 0.6 keV and 0.11 keV. We argue that these components arise in discrete (almost monothermal) plasmas. Moreover, they cannot be produced within an integral gas structure or by the cooling of a dominant hot process. Consistent with earlier findings, we also find that the Fe abundance arising from K-shell ions is significantly subsolar and less than the Fe abundance from L-shell ions. We also find novel properties not present in the earlier Chandra spectrum, including a dramatic decrease in the local photoelectric absorption of soft X-rays, a decrease in the strength of the Fe and possibly of the Si K fluorescence features, underpredicted lines in two ions each of Ne and N (suggesting abundances that are ∼1.5–3× and ∼4× solar, respectively), and broadening of the strong Ne X Lyα and O VIII Lyα lines. In addition, we note certain traits in the γ Cas spectrum that are different from those of the fairly well studied analog HD 110432 in this sense the stars have different “personalities.” In particular, for γ Cas the hot X-ray component remains nearly constant in temperature, and the photoelectric absorption of the X-ray plasmas can change dramatically. As found by previous investigators of γ Cas, changes in flux, whether occurring slowly or in rapidly evolving flares, are only seldomly accompanied by variations in hardness. Moreover, the light curve can show a “periodicity” that is due to the presence of flux minima that recur semiregularly over a few hours, and which can appear again at different epochs. A&A, 2010, 512, 22

A Systematic Study of Hα Proﬁles of Be Stars J. Silaj1, C. E. Jones1, C. Tycner2, T. A. A. Sigut1, and A. D. Smith2 1 Department of Physics and Astronomy, The University of Western Ontario, London, Ontario, N6A 3K7, Canada 2 Department of Physics, Central Michigan University, Mt. Pleasant, MI 48859, USA

We present a set of theoretical Hα emission-line profiles of Be stars, created by systematically varying model input parameters over a wide range of accepted values. Models were generated with a non-LTE radiative transfer code that incorporates a non-isothermal disk structure and a solar-type chemical composition. The theoretical Hα emission-line profiles were compared to a large set of Be star spectra with the aim of reproducing their global characteristics. We find that the observed profile shapes cannot be used to uniquely determine the inclination angle of Be star+disk systems. Drastically different profile shapes arise at a given inclination angle as a direct result of the state of the gas, and self-consistent disk physical conditions are therefore crucial for interpreting the observations. ApJS, 2010, 187, 228

2012, Be Star Newsletter, 40 − 67 High-dispersion spectroscopic monitoring of the Be/X-ray binary A0535+26/V725 Tau - I. The long-term proﬁle variability

Y. Moritani1, D. Nogami2, A. T. Okazaki3, A. Imada4, E. Kambe4, S. Honda5, O. Hashimoto5, Y. Ishino1, Y. Suzuki1, and J. Tanaka1 1 Department of Astronomy, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan 2 Kwasan Observatory, Kyoto University, Yamashina-ku, Kyoto 607-8471, Japan 3 Faculty of Engineering, Hokkai-Gakuen University, Toyohira-ku, Sapporo 062-8605, Japan 4 Okayama Astrophysical Observatory, National Astronomical Observatory of Japan, 3037-5 Honjo, Asakuchi, Okayama 719-0232, Japan 5 Gunma Astronomical Observatory, Takayama-mura, Gunma 377-0702, Japan

We report on optical high-dispersion spectroscopic monitoring observations of the Be/X- ray binary A0535+26/V725 Tau, carried out from November 2005 to March 2009. The main aim of these monitoring observations is to study spectral variabilities in the Be disc, on both the short (a week or so) and long (more than hundreds of days) time-scales, by taking long-term frequent observations. Our four-year spectroscopic observations indicate that the V/R ratio, i.e., the relative intensity of the violet (V ) peak to the red (R) one, of the double-peaked H-alpha line profile varies with a period of 500 days. The H-beta line profile also varies in phase with the H-alpha profile. With these observations covering two full cycles of the V/R variability, we reconstruct the 2-D structure of the Be disc by applying the Doppler tomography method to the H-alpha and H-beta emission line profiles, using a rigidly rotating frame with the V/R variability period. The resulting disc structure reveals non-axisymmetric features, which can be explained by a one-armed perturbation in the Be disc. It is the first time that an eccentric disc structure is directly detected by using a method other than the interferometric one. MNRAS, 2010, 405, 467

Properties and nature of Be stars: 27. Orbital and recent long-term variations of the Pleiades Be star Pleione = BU Tau J. Nemravová1, P. Harmanec1, J. Kubát2, P. Koubský2, L. Iliev3, S. Yang4, J. Ribeiro5, M. Slechtaˇ 2, L. Kotková2, M. Wolf1, and P. Skodaˇ 2 1 Astronomical Institute of the Charles University, Faculty of Mathematics and Physics, V Holeˇsoviˇckách 2, CZ-180 00 Praha 8, Czech Republic 2 Astronomical Institute of the Academy of Sciences, CZ-251 65 Ondˇrejov, Czech Republic 3 Institute of Astronomy, Bulgarian Academy of Sciences, BG-1784, 72 Tsarigradsko Chaussee Blvd., Sofia, Bulgaria 4 Physics & Astronomy Department, University of Victoia, PO Box 3055 STN CSC, Victoria, BC, V8W 3P6, Canada 5 Observatóriodo Instituto Geográfico do Exército,R. Venezuela 29, 3 Esq. 1500-618, Lisboa, Portugal

Radial-velocity variations of the H-alpha emission measured on the steep wings of the H-alpha line, prewhitened for the long-time changes, vary periodically with a period of 218.025 ± 0.022 d, conﬁrming the suspected binary nature of the bright Be star BU Tauri, a member of the Pleiades cluster. The orbit seems to have a high eccentricity over 0.7, but

2012, Be Star Newsletter, 40 − 68 we also briefly discuss the possibility that the true orbit is circular and that the eccentricity is spurious owing to the phase-dependent effects of the circumstellar matter. The projected angular separation of the spectroscopic orbit is large enough to allow the detection of the binary with large optical interferometers, provided the magnitude difference primary − secondary is not too large. Since our data cover the onset of a new shell phase up to development of a metallic shell spectrum, we also briefly discuss the recent long-term changes. We confirm the formation of a new envelope, coexisting with the previous one, at the onset of the new shell phase. We find that the full width at half maximum of the H-alpha profile has been decreasing with time for both envelopes. In this connection, we briefly discuss Hirata’s hypothesis of precessing gaseous disk and possible alternative scenarios of the observed long-term changes. A&A, 2010, 516, 80

Can massive Be/Oe stars be progenitors of long gamma ray bursts?

C. Martayan1,2, J. Zorec3, Y. Frémat4, and S. Ekström5 1 European Organization for Astronomical Research in the Southern Hemisphere, Alonso de Cordova 3107, Vitacura, Santiago de Chile, Chile 2 GEPI, Observatoire de Paris, CNRS, UniversitéParis Diderot, 5 place Jules Janssen, 92195 Meudon Cedex, France 3 Institut d’Astrophysique de Paris, UMR7095, CNRS, UniversitéMarie & Pierre Curie, 98bis Boulevard Arago 75014 Paris, France 4 Royal Observatory of Belgium, 3 avenue circulaire, 1180 Brussels, Belgium 5 Geneva Observatory, University of Geneva, Maillettes 51, 1290 Sauverny, Switzerland

Context. The identification of long-gamma-ray-bursts (LGRBs) is still uncertain, although the collapsar engine of fast-rotating massive stars is gaining a strong consensus. Aims. We propose that low-metallicity Be and Oe stars, which are massive fast rotators, are potential LGRB progenitors. Methods. We checked this hypothesis by 1) testing the global specific angular momentum of Oe/Be stars in the ZAMS with the SMC metallicity; 2) comparing the ZAMS (Ω/Ωc, M/M ) parameters of these stars with the area predicted theoretically for progenitors with metallicity Z = 0.002; and 3) calculating the expected rate of LGRBs/year/galaxy and comparing them with the observed ones. To this end, we determined the ZAMS linear and angular rotational velocities for SMC Be and Oe stars using the observed v sin i parameters, corrected from the underestimation induced by the gravitational darkening effect. Results. The angular velocities of SMC Oe/Be stars are on average hΩ/Ωci = 0.95 in the ZAMS. These velocities are in the area theoretically predicted for the LGRBs progenitors. We estimated the yearly rate per galaxy of LGRBs and the number of LGRBs produced in the local Universe up to z = 0.2. We have considered that the mass range of LGRB progenitors corresponds to stars hotter than spectral types B0–B1 and used individual beaming ◦ pred −7 −6 angles from 5 to 15 . We thus obtain RLGRB ∼ 10 to ∼ 10 LGRBs/year/galaxy, which represents on average 2 to 14 LGRB predicted events in the local Universe during the past 11 years. The predicted rates could widely surpass the observed ones [(0.2-3)×10−7 LGRBs/year/galaxy; 8 LGRBs observed in the local Universe during the last 11 years] if the stellar counts were made from the spectral type B1–B2, in accordance with the expected apparent spectral types of the appropriate massive fast rotators.

2012, Be Star Newsletter, 40 − 69 Conclusion. We conclude that the massive Be/Oe stars with SMC metallicity could be LGRBs progenitors. Nevertheless, other SMC O/B stars without emission lines, which have high enough speciﬁc angular momentum, can enhance the predicted RLGRB rate. A&A, 2010, 516, 103

The binary fraction and mass-ratio of Be and B stars: a comparative VLT/NACO study Ren´eOudmaijer and Andy Parr 1 School of Physics and Astronomy, University of Leeds, LEEDS LS2 9JT, UK

In order to understand the formation mechanism of the disks around Be stars it is imperative to have a good overview of both the differences and similarities between normal B stars and the Be stars. Here we investigate a previous report that there may be a large population of sub-arcsecond companions to Be stars. We present the first systematic, comparative imaging study of the binary properties of matched samples of B and Be stars observed using the same equipment. We obtained high angular resolution (0.07–0.1 arcsec) K band Adaptive Optics data of 40 B stars and 39 Be stars. The separations that can be probed range from 0.1 to 8 arcsec (corresponding to 20–1000 AU), and magnitude differences up to 10 magnitudes can in principle be covered. We detect 11 binaries out of 37 Be targets (corresponding to a binary fraction of 30 ± 8%) and 10 binaries out of 36 B targets (29 ± 8%). Further tests demonstrate that the B and Be binary systems are not only similar in frequency but also remarkably similar in terms of binary separations, flux differences and mass ratios. We find that any hypotheses invoking binary companions as responsible for the formation of a disk need the companions to be closer than 20 AU. Close companions are known to affect the circumstellar disks of Be stars, but as not all Be stars have been found to be close binaries, the data suggest that binarity can not be responsible for the Be phenomenon in all Be stars. Finally, the similarities of the binary parameters themselves also shed light on the Be formation mechanism. They strongly suggest that the initial conditions that gave rise to B and Be star formation must, to all intents and purposes, be similar. This in turn indicates that the Be phenomenon is not the result of a different star formation mechanism. MNRAS, 2010, 405, 2439

Photometry of two unusual A supergiant systems in the Small Magellanic Cloud R. E. Mennickent1, M. Smith2, Z. Kolaczkowski 1,3, G. Pietrzyński4, and I. Soszyński4 1 Departamento de Astronom´ıa,Facultad de Ciencias F´ısicas y Matemáticas,Universidad de Concepción, Casilla 160-C, Concepción, Chile 2 Department of Physics, Catholic University of America, Washington, DC 20064, USA; Present address: Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218, USA 3 Instytut Astronomiczny Uniwersytetu Wroclawskiego, Kopernika 11, 51-622 Wroclaw, Poland 4 Warsaw University Observatory, Al. Ujazdowskie 4, 00-478 Warszawa, Poland

We present multiwavelength broadband photometry and V,I time resolved photometry for two variable bright stars in the SMC, OGLE004336.91-732637.7 (SMC-SC3) and

2012, Be Star Newsletter, 40 − 70 OGLE004633.76-731204.3 (SMC-SC4). The light curves span 12 years and show long- term periodicities (SMC-SC3) and modulated eclipses (SMC-SC4) that are discussed in terms of wide-orbit intermediate mass interacting binaries and associated envelopes. SMC- SC3 shows a primary period of 238.1 days along with a complicated waveform suggesting ellipsoidal variablity inﬂuenced by an eccentric orbit. This star also shows a secondary variability with an unstable periodicity that has a mean value of 15.3 days. We suggest this could be associated with nonradial pulsations. PASP, 2010, 122, 662

High dispersion spectroscopy of two A supergiant systems in the Small Magellanic Cloud with novel properties R. E. Mennickent1 and M.A. Smith2 1 Universidad de Concepci´on,Departamento de Astronom´ıa,Casilla 160-C, Concepci´on,Chile 2 Department of Physics, Catholic University of America, Washington, DC 20064, USA; Present address: Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218, USA

We present the results of a spectroscopic investigation of two novel variable bright blue stars in the SMC, OGLE004336.91-732637.7 (SMC-SC3) and the periodically occulted star OGLE004633.76-731204.3 (SMC-SC4), whose photometric properties were reported by Mennickent et al. (2010). High-resolution spectra in the optical and far-UV show that both objects are actually A + B type binaries. Three spectra of SMC-SC4 show radial velocity variations, consistent with the photometric period of 184.26 days found in Men- nickent et al. 2010. The optical spectra of the metallic lines in both systems show combined absorption and emission components that imply that they are formed in a flattened envelope. A comparison of the radial velocity variations in SMC-SC4 and the separation of the V and R emission components in the H-alpha emission profile indicate that this envelope, and probably also the envelope around SMC-SC3, is a circumbinary disk with a characteristic orbital radius some three times the radius of the binary system. The optical spectra of SMC- SC3 and SMC-SC4 show, respectively, He I emission lines and discrete Blue Ab- sorption Components (“BACs”) in metallic lines. The high excitations of the He I lines in the SMC-SC3 spectrum and the complicated variations of Fe II emission and absorption components with orbital phase in the spectrum of SMC-SC4 suggests that shocks occur between the winds and various static regions of the stars’ co-rotating binary-disk complexes. We suggest that BACs arise from wind shocks from the A star impacting the circumbinary disk and a stream of former wind-efflux from the B star accreting onto the A star. The latter picture is broadly similar to mass transfer occurring in the more evolved (but less massive) Algol (B/A + K) systems, except that we envision transfer occurring in the other direction and not through the inner Lagrangian point. Accordingly, we dub these objects prototype of a small group of Magellanic Cloud wind-interacting A + B binaries. MNRAS, 2010, 407, 734

2012, Be Star Newsletter, 40 − 71 The 13Carbon footprint of B[e] supergiants

A. Liermann1,2, M. Kraus3, O. Schnurr4,5, and M. Borges Fernandes6 1 UniversitätPotsdam, Institut fürPhysik und Astronomie, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany 2 Max-Planck-Institut fürRadioastronomie, Auf dem Hügel69, 53121 Bonn, Germany 3 Astronomickýústav, Akademie vˇed Ceskérepubliky,ˇ Friˇcova 298, 251 65 Ondˇrejov, Czech Republic 4 University of Sheffield, Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, UK 5 Astrophysikalisches Institut Potsdam, An der Sternwarte 16, 14482 Potsdam, Germany 6 ObservatórioNacional, Rua General JoséCristino 77, 20921-400 SãoCristovão,Rio de Janeiro, Brazil

We report on the first detection of 13C enhancement in two B[e] supergiants in the Large Magellanic Cloud. Stellar evolution models predict the surface abundance in 13C to strongly increase during main-sequence and post-main sequence evolution of massive stars. However, direct identification of chemically processed material on the surface of B[e] supergiants is hampered by their dense, disk-forming winds, hiding the stars. Recent theoretical computations predict the detectability of enhanced 13C via the molecular emission in 13CO arising in the circumstellar disks of B[e] supergiants. To test this potential method and to unambiguously identify a post-main sequence B[e]SG by its 13CO emission, we have obtained high-quality K-band spectra of two known B[e] supergiants in the Large Magellanic Cloud, using the Very Large Telescope’s Spectrograph for INtegral Field Observation in the Near-Infrared (VLT/SINFONI). Both stars clearly show the 13CO band emission, whose strength implies a strong enhancement of 13C, in agreement with theoretical predictions. This first ever direct confirmation of the evolved nature of B[e] supergiants thus paves the way to the first identification of a Galactic B[e] supergiant. MNRAS, 2010, 408, L6

Spectroscopic analysis of the B/Be visual binary HR 1847

J. Kubát1, S. M. Saad2 A. Kawka1, M. I. Nouh2, L. Iliev3, K. Uytterhoeven4, D. Korˇcáková1, P. Hadrava5, P. Skodaˇ 1, V. Votruba1,6, M. Dovˇciak5, and M. Slechtaˇ 1 1 Astronomickýústav, Akademie vˇed Ceskérepubliky,ˇ CZ-251 65 Ondˇrejov, Czech Republic 2 National Research Institute of Astronomy and Geophysics, 11421 Helwan, Cairo, Egypt 3 Institute of Astronomy, Bulgarian Academy of Sciences, 72 Tsarigradsko Shossee Blvd., BG-1784 Sofia, Bulgaria 4 Laboratoire AIM, CEA/DSM-CNRS-UniversitéParis Diderot, CEA, IRFU, SAp, Centre de Saclay, F- 91191 Gif-sur-Yvette, France 5 Astronomickýústav, Akademie vˇed Ceskérepubliky,ˇ Boˇcn´ıII 1401, CZ-141 31 Praha 4, Czech Republic 6 Ustav´ teoretickéfyziky a astrofyziky PˇrFMU, Kotláˇrská2, CZ-611 37 Brno, Czech Republic

We studied both components of a slightly overlooked visual binary HR 1847 spectroscopically to determine its basic physical and orbital parameters. Basic stellar parameters were determined by comparing synthetic spectra to the observed echelle spectra, which cover both the optical and near-IR regions. New observations of this system used the Ondˇrejov and Rozhen 2-m telescopes and their coud´espectrographs. Radial velocities from individual spectra were measured and then analysed with the code FOTEL to determine orbital

2012, Be Star Newsletter, 40 − 72 parameters. The spectroscopic orbit of HR 1847 A is presented for the first time. It is a single-lined spectroscopic binary with a B-type primary, a period of 719.79 days, and a highly eccentric orbit with e = 0.7. We confirmed that HR 1847 B is a Be star. Its Hα emission significantly decreased from 2003 to 2008. Both components have a spectral type B7–8 and luminosity class IV–V. A&A, 2010, 520, 103

Probing Local Density Inhomogeneities in the Circumstellar Disk of a Be Star Using the New Spectro-astrometry Mode at the Keck Interferometer J.-U. Pott1,2,3, J. Woillez2, S. Ragland2, P. L. Wizinowich2, J. A. Eisner4, J. D. Monnier5, R. L. Akeson6, A. M. Ghez3,7, J. R. Graham8, L. A. Hillenbrand9, R. Millan-Gabet6, E. Appleby2, B. Berkey2, M. M. Colavita10, A. Cooper2, C. Felizardo6, J. Herstein6, M. Hrynevych2, D. Medeiros2, D. Morrison2, T. Panteleeva2, B. Smith2, K. Summers2, K. Tsubota2, C. Tyau2, and E. Wetherell2 1 Max-Planck-Institut f¨urAstronomie, K¨onigstuhl17, D-69117 Heidelberg, Germany 2 W. M. Keck Observatory, California Association for Research in Astronomy, Kamuela, HI 96743 3 Division of Astronomy and Astrophysics, University of California, Los Angeles, CA 90095-1547 4 Steward Observatory, University of Arizona, Tucson, AZ 85721 5 Astronomy Department, University of Michigan, Ann Arbor, MI 48109 6 NASA Exoplanet Science Institute, Caltech, Pasadena, CA 91125 7 Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA 8 Astronomy Department, University of California Berkeley, CA 94720 9 California Institute of Technology, Pasadena, CA 91125 10 Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109

We report on the successful science verification phase of a new observing mode at the Keck Interferometer, which provides a line-spread function width and sampling of 150 km s−1 at the K0-band, at a current limiting magnitude of K0 ∼ 7 mag with a spatial resolution of λ/2 B ≈ 2.7 mas and a measured differential phase stability of unprecedented precision (3 mrad at K = 5 mag, which represents 3 µas on the sky or a centroiding precision of 10−3). The scientific potential of this mode is demonstrated by the presented observations of the circumstellar disk of the evolved Be star 48 Lib. In addition to indirect methods such as multi-wavelength spectroscopy and polarimetry, the spectro-interferometric astrometry described here provides a new tool to directly constrain the radial density structure in the disk. For the first time, we resolve several Pfund emission lines, in addition to Brγ, in a single interferometric spectrum, with adequate spatial and spectral resolution and precision to analyze the radial disk structure in 48 Lib. The data suggest that the continuum and Pf emission originates in significantly more compact regions, inside the Brγ-emission zone. Thus, spectro-interferometric astrometry opens the opportunity to directly connect the different observed line profiles of Brγ and Pfund in the total and correlated flux to different disk radii. The gravitational potential of a rotationally flattened Be star is expected to in- duce a one-armed density perturbation in the circumstellar disk. Such a slowly rotating disk oscillation has been used to explain the well-known periodic V/R spectral profile variability in these stars, as well as the observed V/R cycle phase shifts between different disk emission lines. The differential line properties and linear constraints set by our data are consistent with theoretical models and lend direct support to the existence of a radius-dependent disk

2012, Be Star Newsletter, 40 − 73 density perturbation. The data also show decreasing gas rotation velocities at increasing stellocentric radii as expected for Keplerian disk rotation, assumed by those models. ApJ, 2010, 721, 802

Spectro-interferometry of the Be star δ Sco: Near-Infrared Continuum and Gas Emission Region Sizes in 2007

R. Millan-Gabet1, J. D. Monnier2, Y. Touhami3, et al. 1 California Institure of Technology, NASA Exoplanet Science Institute 2 University of Michigan, Department of Astronomy 3 Georgia State University, Department of Physics and Astronomy

We present near-infrared H and K-band spectro-interferometric observations of the gaseous disk around the primary Be star in the δ Sco binary system, obtained in 2007 (between periastron passages in 2000 and 2011). Observations using the CHARA/MIRC instrument at H-band resolve an elongated disk with a Gaussian FWHM 1.18 × 0.91 mas. Using the Keck Interferometer, the source of the K-band continuum emission is only marginally spatially resolved, and consequently we estimate a relatively uncertain K-band continuum disk FWHM of 0.7 ± 0.3 mas. Line emission on the other hand, He I λ2.0583 µm and Brγ λ2.1657 µm, is clearly detected, with ∼ 10% lower visibilities than those of the continuum. When taking into account the continuum/line flux ratio this translates into much larger sizes for the line emission regions: 2.2 ± 0.4 mas and 1.9 ± 0.3 mas for He I and Brγ respectively. Our KI data also reveal a relatively flat spectral differential phase response, ruling out significant off-center emission. We expect these new measurements will help constrain dynamical models being actively developed in order to explain the disk formation process in the δ Sco system and Be stars in general. ApJ, 2010, 723, 544

Stellar Winds in Interaction - Proceedings of the international ProAm workshop on stellar winds Convento da Arrabida, Portugal, 2010 May 29 – June 2

T. Eversberg1 and J. Knapen2 1 SchnörringenTelescope Science Institute (STScI), Am Kielshof 21a, 51105 Köln,Germany 2 Instituto de Astrofisica de Canarias, E-38200 La Laguna, Tenerife, Spain

We are presently in the “Golden Age of Astronomy”. Professional telescopes reached the 10 m limit and semiconductors displaced chemicals-based data acquisition in the form of photographic plates. This also influences amateur astronomy. Technical equipment becomes much cheaper and telescope apertures of the order of 40 cm are no longer an exception. The amateur can thus in principle use the same technologies as the professional astronomer and since the early 1990s many advanced amateur astronomers have discovered the field of stellar spectroscopy. There is an important gap in professional astronomy which can be filled by amateur astronomers and their smaller telescopes. Some stellar phenomena need longer time coverage,

2012, Be Star Newsletter, 40 − 74 of order, e.g., some weeks. This is especially valid for binary stars. One such interesting target is WR 140, a WR+O binary with a highly eccentric orbit and a period of about 8 years. The observation of its periastron passage in the visible wavelength range is valuable for measurements in other wavelength domains to understand the wind-wind interaction of both components and the global geometry and physics of the system. For this and some other massive star targets, a group of amateur and professional astronomers wrote a successful proposal for 116 nights at the 50 cm Mons telescope at Teide observatory on Tenerife, supported by the Instituto de Astrof´ısicade Canarias (IAC). The group of observers was a mix of enthusiastic astronomers from various professions (e.g., physicists, a physics student, a chemist, a physician, a schoolboy, a pilot) but they all have been experienced observers. A concluding meeting for ﬁrst-hand presentations took place at the Convento da Arrabida, an old monastery close to Lisbon in Portugal, from May 29 to June 2, 2010. Many campaign participants came together and discussed results of X-ray, visual, IR and radio observations, as well as aspects of future ProAm campaigns. These proceedings contain the written version of most of the presentations at the workshop, and highlight some of the initial results of our campaign. As a direct consequence of our meeting we established the new ProAm Convento Group (http://www.stsci.de/convento/) which will support future collaborations between amateur and professional astronomers. Preprints from [email protected] or on the web at http://www.stsci.de/pdf/arrabida.pdf

A New Diagnostic of the Radial Density Structure of Be Disks Zachary H. Draper1, John P. Wisniewski1,2, Karen S. Bjorkman3, Xavier Haubois4, Alex C. Carciofi4, Jon E. Bjorkman3, Marilyn R. Meade5, and Atsuo Okazaki6 1 University of Washington, Department of Astronomy 2 NSF Astronomy & Astrophysics Postdoctoral Fellow 3 University of Toledo, Department of Physics and Astronomy 4 Universidade de SãoPaulo, Instituto de Astronomia, Geof´ısicae CiênciasAtmosféricas 5 University of Wisconsin, Space Astronomy Lab 6 Hokkai-Gakuen University, Faculty of Engineering

We analyze the intrinsic polarization of two classical Be stars in the process of losing their circumstellar disks via a Be to normal B star transition originally reported by Wisniewski et al. During each of five polarimetric outbursts which interupt these disk-loss events, we find that the ratio of the polarization across the Balmer jump (BJ+/BJ−) versus the V -band polarization traces a distinct loop structure as a function of time. Since the polarization change across the Balmer jump is a tracer of the innermost disk density whereas the V -band polarization is a tracer of the total scattering mass of the disk, we suggest such correlated loop structures in Balmer jump-V band polarization diagrams (BJV diagragms) provide a unique diagnostic of the radial distribution of mass within Be disks. We use the 3-D Monte Carlo radiation transfer code HDUST to reproduce the observed clockwise loops simply by turning “on/off” the mass decretion from the disk. We speculate that counter-clockwise loop structures we observe in BJV diagrams might be caused by the mass decretion rate changing between subsequent “on/off” sequences. Applying this new diagnostic to a larger

2012, Be Star Newsletter, 40 − 75 sample of Be disk systems will provide insight into the time-dependent nature of each system’s stellar decretion rate. ApJL, 2011, 728, 40

On the nature of the Be star HR 7409 (7 Vul) S. Vennes1, A. Kawka1, S. Jonić2, I. Pirković2, L. Iliev3, J. Kubát1, M. Slechtaˇ 1, P. Németh1, and M. Kraus1 1 Astronomickýústav AV CR,ˇ Friˇcova 298,CZ-251 65 Ondˇrejov, Czech Republic 2 Department of Astronomy, Faculty of Mathematics, University of Belgrade, Studenski trg 16, 11000 Bel- grade, Serbia 3 Institute of Astronomy, Bulgarian Academy of Sciences, 72 Tsarigradsko Shossee Blvd., 1784 Sofia, Bul- garia

HR 7409 (7 Vul) is a newly identiﬁed Be star possibly part of the Gould Belt and is the massive component of a 69-day spectroscopic binary. The binary parameters and properties of the Be star measured using high-dispersion spectra obtained at Ondrejov Observatory and at Rozhen Observatory imply the presence of a low mass companion (∼ 0.5–0.8 M ). If the pair is relatively young (< 50–80 Myr), then the companion is a KV star, but, following another, older evolutionary scenario, the companion is a horizontal-branch star or possibly a white dwarf star. In the latter scenario, a past episode of mass transfer from an evolved star onto a less massive dwarf star would be responsible for the peculiar nature of the present-day, fast-rotating Be star. MNRAS, 2011, 413, 2760

The Infrared Continuum Sizes of Be Star Disks Y. Touhami1, D. R. Gies1, G. H. Schaefer2 1 Center for High Angular Resolution Astronomy and Department of Physics and Astronomy, Georgia State University, P.O. Box 4106, Atlanta, GA 30302-4106 2 Georgia State University, CHARA Array, P.O. Box 48, Mount Wilson, CA 91023

We present an analysis of the near-infrared continuum emission from the circumstellar gas disks of Be stars using a radiative transfer code for a parametrized version of the viscous decretion disk model. This isothermal gas model creates predicted images that we use to estimate the HWHM emission radius along the major axis of the projected disk and the spatially integrated flux excess at wavelengths of 1.7, 2.1, 4.8, 9, and 18 µm. We discuss in detail the effect of the disk base density, inclination angle, stellar effective temperature, and other physical parameters on the derived disk sizes and color excesses. We calculate color excess estimates relative to the stellar V -band flux for a sample of 130 Be stars using photometry from 2MASS and the AKARI infrared camera all-sky survey. The color excess relations from our models make a good match of the observed color excesses of Be stars. We also present our results on the projected size of the disk as a function of wavelength for the classical Be star ζ Tauri, and we show that the model predictions are consistent with interferometric observations in the H, K0, and 12 µm bands. ApJ, 2011, 729, 17

2012, Be Star Newsletter, 40 − 76 The Revised Orbit of the δ Sco System C. Tycner1, A. Ames1, R. T. Zavala2, C. A. Hummel3, J. A. Benson2, and D. J. Hutter2 1 Department of Physics, Central Michigan University, Mount Pleasant, MI 48859 2 US Naval Observatory, Flagstaff Station, 10391 W. Naval Observatory Rd., Flagstaff, AZ 86001 3 European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching bei München, Germany

In anticipation of the possible collision between a circumstellar disk and the secondary star in the highly eccentric binary system δ Scorpii, high angular resolution interferometric observations have been acquired aimed at revising the binary parameters. The Navy Pro- totype Optical Interferometer (NPOI) was used to spatially resolve the binary components in 2000 and over a period between 2005 and 2010. The interferometric observations are used to obtain the angular separations and orientations of the two stellar components at all epochs for which data has been obtained, including 2005 and 2006, for which based on previous studies there was some uncertainty as to if the signature of binarity can be clearly detected. The results of this study represent the most complete and accurate coverage of the binary orbit of this system to date and allow for the revised timing of the upcoming periastron passage that will occur in 2011 to be obtained. ApJL, 2011, 729, 5

The Variability of Hα Equivalent Widths in Be Stars C. E. Jones1, C. Tycner2, and A. D. Smith2 1 Department of Physics and Astronomy, The University of Western Ontario, London, Ontario, N6A 3K7, Canada 2 Department of Physics, Central Michigan University, Mt. Pleasant, MI 48859, USA

Focusing on B-emission stars, we investigated a set of Hα equivalent widths calculated from observed spectra acquired over a period of about 4 years from 2003 to 2007. During this time, changes in equivalent width for our program stars were monitored. We have found a simple statistical method to quantify these changes in our observations. This statistical test, commonly called the F ratio, involves calculating the ratio of the external and internal error. We show that the application of this technique can be used to place bounds on the degree of variability of Be stars. This observational tool provides a quantitative way to ﬁnd Be stars at particular stages of variability requiring relatively little observational data. AJ, 2011, 141, 150

2012, Be Star Newsletter, 40 − 77 Hydrodynamic Interaction between the Be Star and the Pulsar in the TeV Binary PSR B1259−63/LS 2883

Atsuo T. Okazaki1, Shigehiro Nagataki2, Tsuguya Naito3, Akiko Kawachi4, Kimitake Hayasaki5, Stanley P. Owocki6, and Jumpei Takata7 1 Faculty of Engineering, Hokkai-Gakuen University Sapporo 062-8605, Japan 2 Yukawa Institute for Theoretical Physics, Kyoto 606-8502, Japan 3 Faculty of Management Information, Yamanashi Gakuin University, Japan 4 Department of Physics, Tokai University, Japan 5 Department Astronomy, Kyoto University, Japan 6 Bartol Research Institute, University of Delaware, USA 7 Department of Physics, University of Hong Kong, Pokfulam Road, China

We study the interaction between the Be star and the pulsar in the TeV binary PSR B1259−63/LS 2883, using 3-D SPH simulations of the tidal and wind interactions in this Be-pulsar system. We first run a simulation without pulsar wind nor Be wind, taking into account only the gravitational effect of the pulsar on the Be disk. In this simulation, the gas particles are ejected at a constant rate from the equatorial surface of the Be star, which is tilted in a direction consistent with multi-waveband observations. We run the simulation until the Be disk is fully developed and starts to repeat a regular tidal interaction with the pulsar. Then, we turn on the pulsar wind and the Be wind. We run two simulations with different wind mass-loss rates for the Be star, one for a B2V type and the other for a significantly earlier spectral type. Although the global shape of the interaction surface between the pulsar wind and the Be wind agrees with the analytical solution, the effect of the pulsar wind on the Be disk is profound. The pulsar wind strips off an outer part of the Be disk, truncating the disk at a radius significantly smaller than the pulsar orbit. Our results, therefore, rule out the idea that the pulsar passes through the Be disk around periastron, which has been assumed in the previous studies. It also turns out that the location of the contact discontinuity can be significantly different between phases when the pulsar wind directly hits the Be disk and those when the pulsar wind collides with the Be wind. It is thus important to adequately take into account the circumstellar environment of the Be star, in order to construct a satisfactory model for this prototypical TeV binary. 2011, PASJ, 63, 893

Near-Contemporaneous Optical Spectroscopic and Infrared Photometric Observations of Candidate Herbig Ae/Be Stars in the Magellanic Clouds Bradley W. Rush1, John P. Wisniewski2, and Karen S. Bjorkman1 1 University of Toledo 2 University of Washington

We present near-IR (J, H, KS) photometry for 27 of the 28 candidate Herbig Ae/Be stars in the Small and Large Magellanic Clouds identified via the EROS1 and EROS2 surveys as well as near-contemporaneous optical (H-alpha) spectroscopy for 21 of these 28 candidates. Our observations extend previous efforts to determine the evolutionary status of these objects. We compare the IR brightness and colors of a subset of our sample with archival ground- based IR data and find evidence of statistically significant photometric differences for ELHC

2012, Be Star Newsletter, 40 − 78 5, 7, 12, 18, and 21 in one or more filter. In all cases, these near-IR photometric variations exhibit a grey color as compared to earlier epoch data. The ∼1 mag IR brightening and minimal change in the H-alpha emission strength we observe in ELHC 7 is consistent with previous claims that it is a UX Ori type HAe/Be star, which is occasionally obscurred by dust clouds. We also detect a ∼1 mag IR brightening of ELHC 12, but find little evidence of a similar large-scale change in its H-alpha line strength, suggesting that its behavior could also be caused by a UX Ori-like event. The ∼0.5 mag IR variability we observe for ELHC 21, which also exhibited little evidence of a change in its H-alpha emission strength, could conceivably be caused by a major recent enhancement in the density of the inner disk region of a classical Be star. We also report the first near-IR photometry for two ESHC stars and the first H-alpha spectroscopy for one ELHC and five ESHC stars. Although H-alpha emission is detected in all of these new observations, they do not exhibit a strong near-IR excess. It is therefore possible that many of these objects may be classical Be stars rather than Herbig Ae/Be stars. AJ, 2011, 142, 58

The Be Star Spectra (BeSS) database

C. Neiner1 B. de Batz1 F. Cochard2,3 M. Floquet4, A. Mekkas4, and V. Desnoux3 1 LESIA, UMR 8109 du CNRS, Observatoire de Paris, UPMC, Univ. Paris Diderot, 5 place Jules Janssen, 92195 Meudon Cedex, France 2 Shelyak Instruments, Les Roussets, 38420 Revel, France 3 ARAS, Astronomical Ring for Access to Spectroscopy 4 GEPI, UMR 8111 du CNRS, Observatoire de Paris, Univ. Paris Diderot, 5 place Jules Janssen, 92195 Meudon Cedex, France

Be stars vary on many timescales, from hours to decades. A long time base of observations to analyse certain phenomena in these stars is therefore necessary. Collecting all existing and future Be star spectra in one database has thus emerged as an important tool for the Be star community. Moreover, for statistical studies, it is useful to have centralised information on all known Be stars via an up-to-date catalogue. These two goals are what the “Be Star Spectra” (BeSS, http://basebe.obspm.fr) database proposes to achieve. The database contains an as-complete-as-possible catalogue of known Be stars with stellar parameters, as well as spectra of Be stars from all origins (any wavelength, any epoch, any resolution, etc). It currently contains above 54 000 spectra of more than 600 diﬀerent Be stars among the ∼2000 Be stars in the catalogue. A user can access and query this database to retrieve information on Be stars or spectra. Registered members can also upload spectra to enrich the database. Spectra obtained by professional as well as amateur astronomers are individually validated in terms of format and science before being included in BeSS. In this paper, we present the database itself, as well as examples of use of BeSS data in terms of statistics and of study of individual stars. AJ, 2011, 142, 149

2012, Be Star Newsletter, 40 − 79 The Thermal Structure of Gravitationally-Darkened Classical Be Star Disks

M. A. McGill1, T. A. A. Sigut1, and C. E. Jones1 1 Department of Physics and Astronomy, The University of Western Ontario, London, Ontario, N6A 3K7, Canada

The effect of gravitational darkening on models of the thermal structure of Be star disks is systematically studied for a wide range of Be star spectral types and rotation rates. Gravitational darkening causes a reduction of the stellar effective temperature towards the equator and a redirection of energy towards the poles. It is an important physical effect in these star-disk systems because the photoionizing radiation from the central B star is the main energy source for the disk. We have added gravitational darkening to the bedisk code to produce circumstellar disk models that include both the variation in the effective temperature with latitude and the non-spherical shape of the star in the calculation of the stellar photoionizing radiation field. The effect of gravitational darkening on global measures of disk temperature is generally significant for rotation rates above 80% of critical rotation. For example, a B0V model rotating at 95% of critical has a density-averaged disk temperature ≈ 2500 K cooler than its non-rotating counterpart. However, detailed differences in the temperature structure of disks surrounding rotating and non-rotating stars reveal a complex pattern of heating and cooling. Spherical gravitational darkening, an approximation that ignores the changing shape of the star, gives good results for disk temperatures for rotation rates less than ≈ 80% of critical. However for the highest rotation rates, the distortion of the stellar surface caused by rotation becomes important. ApJ, 2011, 743, 111

The Temperature Structure of Be Star Disks in the Small Magellanic Cloud

A. Ahmed1,2 and T. A. A. Sigut1 1 Department of Physics and Astronomy, The University of Western Ontario, London, Ontario, CANADA N6A 3K7 2 Department of Astronomy, Cairo University, 12613 Giza, Egypt

The temperature structure of Be star circumstellar disks at the sub-solar metallicity appropriate to the Small Magellanic Cloud (SMC) is investigated. It is found that for central stars of the same spectral type, Be star disks in the SMC are systematically hotter by several thousand degrees compared to Milky Way (MW) disks with the same density structure. For early spectral types (B0e–B3e), this results in systematically smaller Hα equivalent widths for Be stars in the SMC. The implication of this result on Be star frequency comparisons between MW and SMC clusters is shown to be a 5–10% lowering of the detection eﬃciency of Be stars in SMC clusters. These calculations are also compared to the known Hα equivalent width distributions in the MW and SMC. For the MW, reasonable agreement is found; however, for the SMC, the match is not as good and systematically larger Be star disks may be required. ApJ, 2012, 744, 191

2012, Be Star Newsletter, 40 − 80 The first determination of the viscosity parameter in the circumstellar disk of a Be Star Alex C. Carciofi1, Jon E. Bjorkman1,2, SebastiánA. Otero3, Atsuo T. Okazaki4, Stanislav Steflˇ 5, Thomas Rivinius5, Dietrich Baade6, and Xavier Haubois1 1 Instituto de Astronomia, Geof´ısicae CiênciasAtmosféricas,Universidade de SãoPaulo, Rua do Matão 1226, Cidade Universitária,05508-900, SãoPaulo, SP, BRAZIL 2 Ritter Observatory, Department of Physics & Astronomy, Mail Stop 113, University of Toledo, Toledo, OH 43606 3 AAVSO, American Association of Variable Star Observers 4 Faculty of Engineering, Hokkai-Gakuen University, Toyohira-ku, Sapporo 062-8605, Japan 5 European Organization for Astronomical Research in the Southern Hemisphere, Casilla 19001, Santiago 19, Chile 6 European Organization for Astronomical Research in the Southern Hemisphere, Karl-Schwarzschild-Str. 2, 85748 Garching bei München, Germany

Be stars possess gaseous circumstellar decretion disks, which are well described using standard α-disk theory. The Be star 28 CMa recently underwent a long outburst followed by a long period of quiescence, during which the disk dissipated. Here we present the ﬁrst time-dependent models of the dissipation of a viscous decretion disk. By modeling the rate of decline of the V -band excess, we determine that the viscosity parameter α = 1.0 ± 0.2, −8 −1 corresponding to a mass injection rate M˙ = (3.5 ± 1.3) × 10 M yr . Such a large value of α suggests that the origin of the turbulent viscosity is an instability in the disk whose growth is limited by shock dissipation. The mass injection rate is more than an order of magnitude larger than the wind mass loss rate inferred from UV observations, implying that the mass injection mechanism most likely is not the stellar wind, but some other mechanism. ApJL, 2012, 744, 15

Modeling high-energy light curves of the PSR B1259−63/LS 2883 binary based on 3-D SPH simulations J. Takata1, A. T. Okazaki2, S. Nagataki3, T. Naito4, A. Kawachi5, S.-H. Lee3, M. Mori6, K. Hayasaki7, M. S. Yamaguchi8, and S. P. Owocki9 1 Department of Physics, The University of Hong-Kong, Hong Kong 2 Faculty of Engineering, Hokkai-Gakuen University, Toyohira-ku, Sapporo 062-8605, Japan 3 Yukawa Institute for Theoretical Physics, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan 4 Faculty of Management Information, Yamanashi Gakuin University, Kofu, Yamanashi 400-8575, Japan 5 Department of Physics, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan 6 Department of Physical Sciences, Ritsumeikan University, 1-1-1 Noji Higashi, Kusatsu, Shiga 525-8577, Japan 7 Department of Astronomy, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan 8 Department of Earth and Space Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan 9 Bartol Research Institute, University of Delaware, Newark, DE 19716, USA

Temporal changes of X-ray to very-high-energy gamma-ray emissions from the pulsar-Be

2012, Be Star Newsletter, 40 − 81 star binary PSR B1259−63/LS 2883 are studied based on 3-D SPH simulations of pulsar wind interaction with Be-disk and wind. We focus on the periastron passage of the binary and calculate the variation of the synchrotron and inverse-Compton emissions using the simulated shock geometry and pressure distribution of the pulsar wind. The characteristic double-peaked X-ray light curve from observations is reproduced by our simulation under a dense Be disk condition (base density ∼ 10−9 g cm−3). We interpret the pre- and post- periastron peaks as being due to a significant increase in the conversion efficiency from pulsar spin down power to the shock-accelerated particle energy at orbital phases when the pulsar crosses the disk before periastron passage, and when the pulsar wind creates a cavity in the disk gas after periastron passage, respectively. On the contrary, in the model TeV light curve, which also shows a double peak feature, the first peak appears around the periastron phase. The possible effects of cooling processes on the TeV light curve are briefly discussed. ApJ, 2012, 750, 70

The relationship between gamma Cassiopeiae’s X-ray emission and its circumstellar environment M. A. Smith1, R. Lopes de Oliveira2,3, C. Motch4, G. W. Henry5, N. D. Richardson6, K. S. Bjorkman7, Ph. Stee,8, D. Mourard8, J. D. Monnier9, X. Che9, R. Bücke10, E. Pollmann11, D. R. Gies6, G. H. Schaefer6, T. ten Brummelaar6, H. A. McAlister6, N. H. Turner6, J. Sturmann6, L. Sturmann6, and S. T. Ridgway12 1 Catholic University of America, 3700 San Martin Dr., Baltimore, MD 21218, USA 2 Universidade Federal de Sergipe, Departamento de F´ısica, Av. Marechal Rondon s/n, 49100-000 São Cristóvão,SE, Brazil 3 Universidade de SãoPaulo, Instituto de F´ısicade SãoCarlos, Caixa Postal 369, 13560-970, SãoCarlos, SP, Brazil 4 Universitéde Strasbourg, CNRS, Observatoire Astronomique, 11 rue de l’Université,67000 Strasbourg, France 5 Center of Excellence in Information Systems, Tennessee State University, 3500 John Merritt Blvd., Nashville, TN, USA 6 Center for High Angular Resolution Astronomy, Department of Physics and Astronomy, Georgia State University, PO Box 4106, Atlanta, GA 30202-4106, USA 7 Ritter Astrophysical Research Center, Department of Physics & Astronomy, University of Toledo, 2801 W. Bancroft, Toledo, OH 43606, USA 8 Laboratoire Lagrange, UMR 7293 UNS-CNRS-OCA, Bd de l’Observatoire, BP 4229, 06304 Nice Cedex 4, France 9 Department of Astronomy, University of Michigan, Ann Arbor, MI 48109, USA 10 Anna-von-Gierke-Ring 147, 21035 Hamburg, Germany 11 Emil-Nolde-Str. 12, 51375 Leverkusen, Germany 12 National Optical Astronomical Observatory, 950 North Cherry Ave., Tucson, AZ 85719, USA

γ Cas is the prototypical classical Be star and is best known for its variable hard X-ray emission. To elucidate the reasons for this emission, we mounted a multiwavelength campaign in 2010 centered around 4 XMM-Newton observations. The observational techniques included Long Baseline Optical Interferometry (LBOI), monitoring by an Automated Pho- tometric Telescope, and Hα observations. Because γ Cas is also known to be in a binary, we measured Hα radial velocities and redetermined its period as 203.55 ± 0.2 days and an

2012, Be Star Newsletter, 40 − 82 eccentricity near zero. The LBOI observations suggest that the star’s decretion disk was axisymmetric in 2010, has an inclination angle near 45◦, and a larger radius than previously reported. The Be star began an “outburst” at the beginning of our campaign, made visible by a disk brightening and reddening during our campaign. Our analyses of the new high resolution spectra disclosed many attributes found from spectra obtained in 2001 (Chandra) and 2004 (XMM). As well as a dominant hot 14 keV thermal component, these familiar ones included: (i) a fluorescent feature of Fe K stronger than observed at previous times; (ii) strong lines of N VII and Ne XI lines indicative of overabundances; and (iii) a subsolar Fe abundance from K-shell lines but a solar abundance from L-shell ions. We also found that 2 absorption columns are required to fit the continuum. While the first one maintained its historical average of 1×1021cm−2, the second was very large and doubled to 7.4×1023cm−2 during our X-ray observations. Although we found no clear relation between this column density and orbital phase, it correlates well with the disk brightening and reddening both in the 2010 and earlier observations. Thus, the inference from this study is that much (perhaps all?) of the X-ray emission from this source originates behind matter ejected by γ Cas into our line of sight. A&A, 2012, 540, 53

He I 6678 observations of zeta Tauri E. Pollmann1, B. Mauclaire2, and R. B¨ucke3 1 Emil-Nolde-Str. 12, 51375 Leverkusen, Germany 2 Observatoire du Val de l’Arc, Bouches de Rhˆone13, France 3 Anna-von-Gierke-Ring 147, 21035 Hamburg, Germany

We report He I 6678 observations of zeta Tauri, taken between February 2008 until March 2009. We started our long-term observing campaign at the time when the investigations of Ruzdjak et al. (A&A, 2009, 506, 1319) ended, approximately at JD 2454500. The observational data will be published together with this manuscript. IBVS, 2012, 6099, 5

Period analysis of the Hα line proﬁle variation of the binary star pi Aquarii Ernst Pollmann 1 Spektroskopische Arbeitsgemeinschaft ASPA, 51375 Leverkusen, Germany

The V/R measurements in Hα spectra of the binary star π Aqr obtained between Oc- tober 2004 and August 2011, together with the available spectra of the data base BeSS (http://basebe.obspm.fr/basebe/), were subjected to an analysis of a possible periodic behavior using the program AVE (http://www.astrogea.org/soft/ave/aveint.htm). IBVS, 2012, 6023, 1

2012, Be Star Newsletter, 40 − 83 A study of the role of Lyβ ﬂuorescence on O I line strengths in Be stars

Blesson Mathew1, D. P. K. Banerjee1, A. Subramaniam2, and N. M. Ashok1 1 Physical Research Laboratory, Ahmedabad, India 2 Indian Institute of Astrophysics, Bangalore, India

The possibility of the Lyβ fluorescence mechanism being operational in classical Be (CBe) stars and thereby contributing to the strength of the O I λ8446 line has been recognized for long. However, this supposition needs to be quantified by comparing observed and predicted O I line ratios. In the present work, optical and near-infrared spectra of CBe stars are presented. We analyse the observed strengths of the O I λ7774, λ8446, λ11287, and λ13165 lines, which have been theoretically proposed as diagnostics for identifying the excitation mechanism. We have considered and examined the effects of Lyβ fluorescence, collisional excitation, recombination, and continuum fluorescence on these O I line strengths. From our analysis it appears that the Lyβ fluorescence process is indeed operative in Be stars. ApJ, 2012, 753, 13

2012, Be Star Newsletter, 40 − 84 6. MEETINGS

• 2010 Jul 19–23 IAU Symposium 272: “Active OB stars: structure, evolution, mass loss, and critical limits” Paris, France http://iaus272.obspm.fr/ • 2012 Feb 27–Mar 2 Workshop: “Circumstellar Dynamics at High Resolution” Foz do Igua¸cu,Brazil http://www.eso.org/sci/meetings/2012/csdyn.html • 2012 Jul 2–6 11th Hvar Astrophysical Colloquium: “The Most Mysterious Binaries: Sig- niﬁcance for Astrophysics” Hvar, Croatia http://oh.geof.unizg.hr/index.php/en/meetings/xith-hac/ • 2012 Aug 20–31 IAU XXVIII General Assembly Beijing, China http://www.astronomy2012.org/dct/page/1

See http://cadcwww.dao.nrc.ca/meetings/meetings.html for more.

7. LATEX TEMPLATE FOR ABSTRACTS

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2012, Be Star Newsletter, 40 − 85