Radiative Heating and Cooling in Circumstellar Envelopes
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Winter Constellations
Winter Constellations *Orion *Canis Major *Monoceros *Canis Minor *Gemini *Auriga *Taurus *Eradinus *Lepus *Monoceros *Cancer *Lynx *Ursa Major *Ursa Minor *Draco *Camelopardalis *Cassiopeia *Cepheus *Andromeda *Perseus *Lacerta *Pegasus *Triangulum *Aries *Pisces *Cetus *Leo (rising) *Hydra (rising) *Canes Venatici (rising) Orion--Myth: Orion, the great hunter. In one myth, Orion boasted he would kill all the wild animals on the earth. But, the earth goddess Gaia, who was the protector of all animals, produced a gigantic scorpion, whose body was so heavily encased that Orion was unable to pierce through the armour, and was himself stung to death. His companion Artemis was greatly saddened and arranged for Orion to be immortalised among the stars. Scorpius, the scorpion, was placed on the opposite side of the sky so that Orion would never be hurt by it again. To this day, Orion is never seen in the sky at the same time as Scorpius. DSO’s ● ***M42 “Orion Nebula” (Neb) with Trapezium A stellar nursery where new stars are being born, perhaps a thousand stars. These are immense clouds of interstellar gas and dust collapse inward to form stars, mainly of ionized hydrogen which gives off the red glow so dominant, and also ionized greenish oxygen gas. The youngest stars may be less than 300,000 years old, even as young as 10,000 years old (compared to the Sun, 4.6 billion years old). 1300 ly. 1 ● *M43--(Neb) “De Marin’s Nebula” The star-forming “comma-shaped” region connected to the Orion Nebula. ● *M78--(Neb) Hard to see. A star-forming region connected to the Orion Nebula. -
Arxiv:1906.03269V2 [Astro-Ph.EP] 17 Jun 2019
Draft version June 18, 2019 Typeset using LATEX twocolumn style in AASTeX62 The Degree of Alignment Between Circumbinary Disks and Their Binary Hosts 1, 1, 2 3 4 3 Ian Czekala, ∗ Eugene Chiang, Sean M. Andrews, Eric L. N. Jensen, Guillermo Torres, David J. Wilner,3 Keivan G. Stassun,5, 6 and Bruce Macintosh7 1Department of Astronomy, University of California at Berkeley, Campbell Hall, CA 94720-3411, USA 2Department of Earth and Planetary Science, University of California at Berkeley, McCone Hall, Berkeley, CA 94720-4767, USA 3Center for Astrophysics Harvard & Smithsonian, 60 Garden Street, Cambridge, MA 02138, USA j 4Department of Physics and Astronomy, Swarthmore College, 500 College Avenue, Swarthmore, PA 19081, USA 5Department of Physics and Astronomy, Vanderbilt University, 6301 Stevenson Center, Nashville, TN 37235, USA 6Department of Physics, Fisk University, Nashville, TN 37208, USA 7Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, 452 Lomita Mall, Stanford, CA 94305, USA ABSTRACT All four circumbinary (CB) protoplanetary disks orbiting short-period (P < 20 day) double-lined spectroscopic binaries (SB2s)|a group that includes UZ Tau E, for which we present new ALMA data|exhibit sky-plane inclinations idisk which match, to within a few degrees, the sky-plane incli- nations i? of their stellar hosts. Although for these systems the true mutual inclinations θ between disk and binary cannot be directly measured because relative nodal angles are unknown, the near- coincidence of idisk and i? suggests that θ is small for these most compact of systems. We confirm this hypothesis using a hierarchical Bayesian analysis, showing that 68% of CB disks around short-period SB2s have θ < 3:0◦. -
121012-AAS-221 Program-14-ALL, Page 253 @ Preflight
221ST MEETING OF THE AMERICAN ASTRONOMICAL SOCIETY 6-10 January 2013 LONG BEACH, CALIFORNIA Scientific sessions will be held at the: Long Beach Convention Center 300 E. Ocean Blvd. COUNCIL.......................... 2 Long Beach, CA 90802 AAS Paper Sorters EXHIBITORS..................... 4 Aubra Anthony ATTENDEE Alan Boss SERVICES.......................... 9 Blaise Canzian Joanna Corby SCHEDULE.....................12 Rupert Croft Shantanu Desai SATURDAY.....................28 Rick Fienberg Bernhard Fleck SUNDAY..........................30 Erika Grundstrom Nimish P. Hathi MONDAY........................37 Ann Hornschemeier Suzanne H. Jacoby TUESDAY........................98 Bethany Johns Sebastien Lepine WEDNESDAY.............. 158 Katharina Lodders Kevin Marvel THURSDAY.................. 213 Karen Masters Bryan Miller AUTHOR INDEX ........ 245 Nancy Morrison Judit Ries Michael Rutkowski Allyn Smith Joe Tenn Session Numbering Key 100’s Monday 200’s Tuesday 300’s Wednesday 400’s Thursday Sessions are numbered in the Program Book by day and time. Changes after 27 November 2012 are included only in the online program materials. 1 AAS Officers & Councilors Officers Councilors President (2012-2014) (2009-2012) David J. Helfand Quest Univ. Canada Edward F. Guinan Villanova Univ. [email protected] [email protected] PAST President (2012-2013) Patricia Knezek NOAO/WIYN Observatory Debra Elmegreen Vassar College [email protected] [email protected] Robert Mathieu Univ. of Wisconsin Vice President (2009-2015) [email protected] Paula Szkody University of Washington [email protected] (2011-2014) Bruce Balick Univ. of Washington Vice-President (2010-2013) [email protected] Nicholas B. Suntzeff Texas A&M Univ. suntzeff@aas.org Eileen D. Friel Boston Univ. [email protected] Vice President (2011-2014) Edward B. Churchwell Univ. of Wisconsin Angela Speck Univ. of Missouri [email protected] [email protected] Treasurer (2011-2014) (2012-2015) Hervey (Peter) Stockman STScI Nancy S. -
Volatiles in Protoplanetary Disks
Volatiles in Protoplanetary Disks Thesis by Ke Zhang In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy California Institute of Technology Pasadena, California 2015 (Defended May 15, 2015) ii c 2015 Ke Zhang All Rights Reserved iii Acknowledgements First and foremost, I would like to thank my advisor, Geoffrey Blake, for his patience, guidance, support, and inspiration that made this thesis possible. In retrospect, I am so grateful to have chosen Geoff as my mentor. He is a very special kind of advisor, so rare in the fast-paced world, who can be incredibly patient, waiting for a student to find her passion. But once the student has made up her mind, and starts to ask for resources, opportunities, and attention, he is so supportive and resourceful that the only limitation for the student is herself. It was a great privilege working with Geoff, who is ingeniously creative and vastly knowledgeable. Thank you for all the lessons, support, and, most importantly, for believing in and encouraging me. I'm also thankful for John Carpenter who opened for me the wonderful door of (sub)mm-wave interferometry and gave me a very first opportunity to work with ALMA data. John, you are my role model as a rigorous scientist who understands his field profoundly and is dedicated to getting things right. I would also like to thank Colette Salyk for being such a great mentor and a supportive friend during my years in graduate school. Thanks for taking me to the summit of Mauna Kea and beautiful Charlottesville. -
Nov 2016 Newsletter
Volume22, Issue 3 NWASNEWS November 2016 Newsletter for the Wiltshire, Swindon, Beckington WHAT DO WANT FROM YOUR SOCIETY? Astronomical Societies and Salisbury Plain Firstly can I welcome our returning In the early years there may have been Wiltshire Society Page 2 speaker Philip Perkins who last came to more beginners experiences, especially us when we met over the road in the WI where I was learning the hard way myself, Swindon Stargazers 3 hall. not worried about putting my mistakes to the society so, hopefully, they may learn Beckington and SPOG 4 His imaging of the night sky is really in- from my mistakes. spirational, making the transition from Space Place What kind of plan- 5 film (hyposensitising film was no joke) Would somebody like to write a beginners ets could be at Proxima then moving over to digital. piece every month? It doesn't have to be Centauri. all your own work. His work can be seen on his website Space News: Falcon X, 6-13 Astrocruise.com. He has an observatory Saturn’s hex changes colour. in the south of France, but also does a lot At last we have our darker skies with Mars probe crash site. of imaging from here in Wiltshire near longer nights, it may bring cold and some How many planets in Milky Way Aldbourne. cloud, but did you know there are more Pluto and Charon data at last cloudy nights in August than in Decem- Argentine 30tonne meteorite ber? It is just a case of wrapping up warm Formation of the Earth What I have noticed is the drop in sub- and getting out there. -
Scattered Light Observations Versus Disk Models
Master Thesis Unraveling the Transitional Disk RX J1615.3-3255: Scattered Light Observations Versus Disk Models Supervisors: Author: Prof. dr. Inga Kamp Robin Kooistra Prof. Misato Fukagawa July 15, 2014 Image credit: NAOJ Abstract We present a two-stage analysis of the transitional disk RX J1615.3-3255 located in the Lupus association (∼1 Myr old). Using 1.6 µm scattered light, polarized intensity images observed with the HiCIAO instrument of the Subaru Telescope, we deduce the position angle and the inclination angle. The disk is found to extend out to 92 ± 12 AU in the scattered light and no clear structure is observed, nor do we see a central decrease in intensity seen in 880µm continuum observations from the literature. We then analyse two different disk models that are based on the Spectral Energy Distribution (SED). We construct a single-zone, continuous disk model and a multi-zone model with a cavity at 30 AU and a puffed up cavity wall. From these models, we produce simulated images to compare with our observations and submm images from the literature. The multi-zone disk model gives the best reproduction of the observations. Both models show stability against self-gravitation throughout the entire disk, assuming a gas-to-dust ratio of 100. Therefore, the formation of planets through a gravitational instability is unlikely in these models. Contents 1 Introduction & Theory 4 1.1 Protoplanetary Disks in Perspective . 4 1.2 Spectral Energy Distribution & Lada Classification . 5 1.3 Transitional disks . 8 1.4 Polarization in Disks . 9 1.4.1 Stokes Parameters . -
Appendix: Spectroscopy of Variable Stars
Appendix: Spectroscopy of Variable Stars As amateur astronomers gain ever-increasing access to professional tools, the science of spectroscopy of variable stars is now within reach of the experienced variable star observer. In this section we shall examine the basic tools used to perform spectroscopy and how to use the data collected in ways that augment our understanding of variable stars. Naturally, this section cannot cover every aspect of this vast subject, and we will concentrate just on the basics of this field so that the observer can come to grips with it. It will be noticed by experienced observers that variable stars often alter their spectral characteristics as they vary in light output. Cepheid variable stars can change from G types to F types during their periods of oscillation, and young variables can change from A to B types or vice versa. Spec troscopy enables observers to monitor these changes if their instrumentation is sensitive enough. However, this is not an easy field of study. It requires patience and dedication and access to resources that most amateurs do not possess. Nevertheless, it is an emerging field, and should the reader wish to get involved with this type of observation know that there are some excellent guides to variable star spectroscopy via the BAA and the AAVSO. Some of the workshops run by Robin Leadbeater of the BAA Variable Star section and others such as Christian Buil are a very good introduction to the field. © Springer Nature Switzerland AG 2018 M. Griffiths, Observer’s Guide to Variable Stars, The Patrick Moore 291 Practical Astronomy Series, https://doi.org/10.1007/978-3-030-00904-5 292 Appendix: Spectroscopy of Variable Stars Spectra, Spectroscopes and Image Acquisition What are spectra, and how are they observed? The spectra we see from stars is the result of the complete output in visible light of the star (in simple terms). -
Csillagászati Évkönyv
meteor csillagászati évkönyv meteor csillagászati évkönyv 2006 szerkesztette: Mizser Attila Taracsák Gábor Magyar Csillagászati Egyesület Budapest, 2005 A z évkönyv összeállításában közreműködött: Horvai Ferenc Jean Meeus (Belgium) Sárneczky Krisztián Szakmailag ellenőrizte: Szabados László (cikkek, beszámolók) Szabadi Péter (táblázatok) Műszaki szerkesztés és illusztrációk: Taracsák Gábor A szerkesztés és a kiadás támogatói: MLog Műszereket Gyártó és Forgalmazó Kft. MTA Csillagászati Kutatóintézete ISSN 0866-2851 Felelős kiadó: Mizser Attila Készült a G-PRINT BT. nyomdájában Felelős vezető: Wilpert Gábor Terjedelem: 18.75 ív + 8 oldal melléklet Példányszám: 4000 2005. október Csillagászati évkönyv 2006 5 Tartalom Tartalom B evezető.......................................................................................................................... 7 Használati útmutató ...................................................... .......................................... 8 Jelek és rövidítések .................................................................................................. 13 A csillagképek latin és magyar n e v e ........................................................................14 Táblázatok Jelenségnaptár............................................................................................................ 16 A bolygók kelése és nyugvása (ábra) ................................................................. 64 A bolygók a d a ta i.................................................................................................... -
Arxiv:0706.2206V1 [Astro-Ph] 14 Jun 2007 1983; Beichman Et Al
Accepted to the Astrophysical Journal Supplemental Series Preprint typeset using LATEX style emulateapj v. 08/22/09 A CASE STUDY OF LOW-MASS STAR FORMATION Jonathan J. Swift Institute for Astronomy, 2680 Woodlawn Dr., Honolulu, HI 96822-1897: [email protected] William J. Welch Department of Astronomy and Radio Astronomy Laboratory, University of California, 601 Campbell Hall, Berkeley, CA 94720-3411 Accepted to the Astrophysical Journal Supplemental Series ABSTRACT This article synthesizes observational data from an extensive program aimed toward a comprehensive understanding of star formation in a low-mass star-forming molecular cloud. New observations and published data spanning from the centimeter wave band to the near infrared reveal the high and low density molecular gas, dust, and pre-main sequence stars in L1551. The total cloud mass of ∼ 160 M contained within a 0.9 pc has a dynamical timescale, tdyn = 1:1 Myr. Thirty-five pre-main sequence stars with masses from ∼ 0:1 to 1.5 M are selected to be members of the L1551 association constituting a total of 22 ± 5 M of stellar mass. The observed star formation efficiency, SFE = 12%, while the total efficiency, SFEtot, is estimated to fall between 9 and 15%. L1551 appears to have been forming stars for several tdyn with the rate of star formation increas- ing with time. Star formation has likely progressed from east to west, and there is clear evidence that another star or stellar system will form in the high column density region to the northwest of L1551 IRS5. High-resolution, wide-field maps of L1551 in CO isotopologue emission display the structure of the molecular cloud at 1600 AU physical resolution. -
80, June 1994
British Astronomical Association Variable Star Section Circular No 80, June 1994 CONTENTS The Cambridge Variable Star Meeting (continued) 1 New Variable Star Publications 3 Photoelectric Photometry of HU Tauri 3 Photoelectric Photometry of 16 Tauri 4 RAS Grant for VSS Computerisation 4 Selected Medium-Term Light-Curves - Dave McAdam 4 Summaries of IBVS's Nos 3975 to 4006 8 Eclipsing Binary Predictions 9 V409 Persei (=TASV 030645) 12 Professional-Amateur Exchanges Report No 10 - Guy Hurst 13 UK N/SN Recurrent Objects Program Report 1993 - Gary Poyner 17 Making Visual Observations for the Variable Star Section 19 ISSN 0267-9272 Office: Burlington House, Piccadilly, London, W1V 9AG Section Officers Director Tristram Brelstaff, 3 Malvern Court, Addington Road, READING, Berks, RG1 5PL Tel: 0734-268981 Section Melvyn D Taylor, 17 Cross Lane, WAKEFIELD, Secretary West Yorks, WF2 8DA Tel: 0924-374651 Chart John Toone, Hillside View, 17 Ashdale Road, Cressage, Secretary SHREWSBURY, SY5 6DT Tel: 0952-510794 Computer Dave McAdam, 33 Wrekin View, Madeley, TELFORD, Secretary Shropshire, TF7 5HZ Tel: 0952-432048 E-mai1: [email protected]. NET Nova/Supernova Guy M Hurst, 16 Westminster Close, Kempshott Rise, Secretary BASINGSTOKE, Hants, RG22 4PP Tel & Fax: 0256-471074 E-mail: [email protected] GMH@GXVG,AST.CAM.AC.UK Pro-Am Liaison Roger D Pickard, 28 Appletons, HADLOW, Kent TN11 0DT Committee Tel: 0732-850663 Secretary E-mail: [email protected] KENVAD::RDP Eclipsing Binary See Director Secretary Circulars See Director Telephone Alert Numbers Nova and First phone Nova/Supernova Secretary. If only answering Supernova machine response leave message and then try the following: Discoveries Denis Buczynski 0524-68530 Glyn Marsh 0772-690502 Martin Mobberley 0245-475297 (w'kdays) 0284-828431 (w'kends) Variable Star Gary Poyner 021-6053716 Alerts E-mail: [email protected] BHVAD::GP Charges for VSS Publications The following charges are made for the Circulars. -
Numerical Simulations of Stellar Jets and Comparison Between Synthetic and Observed Maps: Clues to the Launch Mechanism
A&A 567, A13 (2014) Astronomy DOI: 10.1051/0004-6361/201322171 & c ESO 2014 Astrophysics Numerical simulations of stellar jets and comparison between synthetic and observed maps: clues to the launch mechanism F. Rubini1, L. Maurri1,G.Inghirami1,2, F. Bacciotti3, and L. Del Zanna1,2,3 1 Dipartimento di Fisica e Astronomia, Università di Firenze, via G. Sansone 1, 50019 Sesto F. no, Firenze, Italy 2 INFN – Sezione di Firenze, via G. Sansone 1, 50019 Sesto F. no, Firenze, Italy 3 INAF – Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy Received 28 June 2013 / Accepted 14 April 2014 ABSTRACT High angular resolution spectra obtained with the Hubble Space Telescope Imaging Spectrograph (HST/STIS) provide rich morpho- logical and kinematical information about the stellar jet phenomenon, which allows us to test theoretical models efficiently. In this work, numerical simulations of stellar jets in the propagation region are executed with the PLUTO code, by adopting inflow condi- tions that arise from former numerical simulations of magnetized outflows, accelerated by the disk-wind mechanism in the launching region. By matching the two regions, information about the magneto-centrifugal accelerating mechanism underlying a given astro- physical object can be extrapolated by comparing synthetic and observed position-velocity diagrams. We show that quite different jets, like those from the young T Tauri stars DG-Tau and RW-Aur, may originate from the same disk-wind model for different config- urations of the magnetic field at the disk surface. This result supports the idea that all the observed jets may be generated by the same mechanism. -
GEORGE HERBIG and Early Stellar Evolution
GEORGE HERBIG and Early Stellar Evolution Bo Reipurth Institute for Astronomy Special Publications No. 1 George Herbig in 1960 —————————————————————– GEORGE HERBIG and Early Stellar Evolution —————————————————————– Bo Reipurth Institute for Astronomy University of Hawaii at Manoa 640 North Aohoku Place Hilo, HI 96720 USA . Dedicated to Hannelore Herbig c 2016 by Bo Reipurth Version 1.0 – April 19, 2016 Cover Image: The HH 24 complex in the Lynds 1630 cloud in Orion was discov- ered by Herbig and Kuhi in 1963. This near-infrared HST image shows several collimated Herbig-Haro jets emanating from an embedded multiple system of T Tauri stars. Courtesy Space Telescope Science Institute. This book can be referenced as follows: Reipurth, B. 2016, http://ifa.hawaii.edu/SP1 i FOREWORD I first learned about George Herbig’s work when I was a teenager. I grew up in Denmark in the 1950s, a time when Europe was healing the wounds after the ravages of the Second World War. Already at the age of 7 I had fallen in love with astronomy, but information was very hard to come by in those days, so I scraped together what I could, mainly relying on the local library. At some point I was introduced to the magazine Sky and Telescope, and soon invested my pocket money in a subscription. Every month I would sit at our dining room table with a dictionary and work my way through the latest issue. In one issue I read about Herbig-Haro objects, and I was completely mesmerized that these objects could be signposts of the formation of stars, and I dreamt about some day being able to contribute to this field of study.