Scott J. Kenyon
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145, September 2010
British Astronomical Association VARIABLE STAR SECTION CIRCULAR No 145, September 2010 Contents EG Andromedae Light Curve ................................................... inside front cover From the Director ............................................................................................... 1 Letter Page. Visual Observing ............................................................................ 4 Epsilon Aurigae Spectroscopically at Mid Eclipse .......................................... 5 Eclipsing Binary News ...................................................................................... 7 AO Cassiopeiae Phase Diagram ............................................................ 9 PV Cephei and Gyulbudaghian’s Nebula ........................................................ 10 WR140 Periastron Campaign Update .............................................................. 12 VSS Meeting, Pendrell Hall. The Central Stars of Planetary Nebulae ............ 14 RR Coronae Borealis 1993-2004 ...................................................................... 16 TU Cassiopeiae Phase Diagram 2005-2010 ..................................................... 18 Binocular Priority List ..................................................................................... 19 Eclipsing Binary Predictions ............................................................................ 20 Charges for Section Publications .............................................. inside back cover Guidelines for Contributing to the Circular ............................. -
Alyssa Goodman, Naomi Ridge, Scott Wolk, Scott Schnee, Di Li & Bryan
COMPLET(E)ING THE STAR-FORMATION HISTORY OF THE RHO-OPH REGION Alyssa Goodman, Naomi Ridge, Scott Wolk, Scott Schnee, Di Li & Bryan Gaensler Background The interaction of newly formed stars with their parent cloud, particularly in the case of massive stars, can have significant consequences for the subsequent development of the cloud. Hot, massive stars will cause cloud disruption through their ionizing flux as well as through the momentum in their stellar winds. Alternatively, given the right conditions in the cloud, stellar winds may also cause the collapse of cloud cores and induce further star formation. Located only 160pc from the Sun, the Ophiuchus molecular cloud is one of the most conspicuous nearby regions where low- and intermediate-mass star formation is taking place (e.g. Wilking 1992 for a review). The Ophiuchus cloud consists of two massive, centrally condensed cores, L1688 and L1689, from each of which a filamentary system of streamers extends to the north-east over tens of parsecs (e.g. Loren 1989). While little star formation activity is observed in the streamers, the westernmost core, L1688 (figure 1), harbors a rich cluster of young stellar objects (YSOs) at various evolutionary stages and is distinguished by a high star-formation efficiency (Wilking & Lada 1983 - hereafter WL83). This young stellar cluster and the cloud core in which it resides are commonly referred to as the ρ-Oph star-forming region. Both the gas/dust content and the embedded stellar population of ρ−Oph have been extensively studied for more than two decades. The distribution of the low-density molecular gas was mapped in C18O(1-0) by WL83, revealing a ridge of high column density gas. -
Arxiv:2012.09981V1 [Astro-Ph.SR] 17 Dec 2020 2 O
Contrib. Astron. Obs. Skalnat´ePleso XX, 1 { 20, (2020) DOI: to be assigned later Flare stars in nearby Galactic open clusters based on TESS data Olga Maryeva1;2, Kamil Bicz3, Caiyun Xia4, Martina Baratella5, Patrik Cechvalaˇ 6 and Krisztian Vida7 1 Astronomical Institute of the Czech Academy of Sciences 251 65 Ondˇrejov,The Czech Republic(E-mail: [email protected]) 2 Lomonosov Moscow State University, Sternberg Astronomical Institute, Universitetsky pr. 13, 119234, Moscow, Russia 3 Astronomical Institute, University of Wroc law, Kopernika 11, 51-622 Wroc law, Poland 4 Department of Theoretical Physics and Astrophysics, Faculty of Science, Masaryk University, Kotl´aˇrsk´a2, 611 37 Brno, Czech Republic 5 Dipartimento di Fisica e Astronomia Galileo Galilei, Vicolo Osservatorio 3, 35122, Padova, Italy, (E-mail: [email protected]) 6 Department of Astronomy, Physics of the Earth and Meteorology, Faculty of Mathematics, Physics and Informatics, Comenius University in Bratislava, Mlynsk´adolina F-2, 842 48 Bratislava, Slovakia 7 Konkoly Observatory, Research Centre for Astronomy and Earth Sciences, H-1121 Budapest, Konkoly Thege Mikl´os´ut15-17, Hungary Received: September ??, 2020; Accepted: ????????? ??, 2020 Abstract. The study is devoted to search for flare stars among confirmed members of Galactic open clusters using high-cadence photometry from TESS mission. We analyzed 957 high-cadence light curves of members from 136 open clusters. As a result, 56 flare stars were found, among them 8 hot B-A type ob- jects. Of all flares, 63 % were detected in sample of cool stars (Teff < 5000 K), and 29 % { in stars of spectral type G, while 23 % in K-type stars and ap- proximately 34% of all detected flares are in M-type stars. -
High-Resolution Spectroscopy of Fu Orionis Stars G
The Astrophysical Journal, 595:384–411, 2003 September 20 # 2003. The American Astronomical Society. All rights reserved. Printed in U.S.A. HIGH-RESOLUTION SPECTROSCOPY OF FU ORIONIS STARS G. H. Herbig Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 P. P. Petrov Crimean Astrophysical Observatory, p/o Nauchny, Crimea 98409, Ukraine1 and R. Duemmler2 Astronomy Division, University of Oulu, P.O. Box 3000, Oulu FIN-90014, Finland Received 2003 February 28; accepted 2003 May 29 ABSTRACT High-resolution spectroscopy was obtained of the FU orionis stars FU Ori and V1057 Cyg between 1995 and 2002 with the SOFIN spectrograph at the Nordic Optical Telescope and with HIRES at Keck I. During these years FU Ori remained about 1 mag (in B) below its 1938–39 maximum brightness, but V1057 Cyg (B 10:5 at peak in 1970–1971) faded from about 13.5 to 14.9 and then recovered slightly. Their photo- spheric spectra resemble that of a rotationally broadened, slightly veiled supergiant of about type G0 Ib, with À1 À1 veq sin i ¼ 70 km s for FU Ori, and 55 km s for V1057 Cyg. As V1057 Cyg faded, P Cyg structure in H and the IR Ca ii lines strengthened and a complex shortward-displaced shell spectrum of low-excitation lines of the neutral metals (including Li i and Rb i) increased in strength, disappeared in 1999, and reappeared in 2001. Several SOFIN runs extended over a number of successive nights so that a search for rapid and cyclic changes in the spectra was possible. -
Variable Stars Observer Bulletin
Amateurs' Guide to Variable Stars September-October 2013 | Issue #2 Variable Stars Observer Bulletin ISSN 2309-5539 Twenty new W Ursae Majoris-type eclipsing binaries from the Catalina Sky Survey Details for 20 new WUMa systems are presented, along with a preliminary The FU Orionis phenomenon model of the FU Orionis stars are pre-main-sequence totally eclipsing eruptive variables which appear to be a system GSC stage in the development of T Tauri 03090-00153. stars. Image: FU Orionis. Credit: ESO NSVS 5860878 = Dauban V 171 Carbon in the sky: A new Mira variable in Cygnus a few remarkable carbon stars The list of the most interesting and bright carbon stars for northern observers is presented. Right: TT Cygni. A carbon star. Credit & Copyright: H.Olofsson (Stockholm Nova Observatory) et al. Delphini 2013 Nova has reached magnitude 4.3 visual The "Heavenly Owl" on August 16 observatory: seeing above the Black Sea waterfront VS-COMPAS Project: variable stars research and data mining. More at http://vs-compas.belastro.net Variable Stars Observer Bulletin Amateurs' Guide to Variable Stars September-October 2013 | Issue #2 C O N T E N T S 04 NSVS 5860878 = Dauban V 171: a new Mira variable in Cygnus by Ivan Adamin, Siarhey Hadon A new Mira variable in the constellation of Cygnus is presented. The variability of the NSVS 5860878 source was detected in January of 2012. Lately, the object was identified as the Dauban V171. A revision is submitted to the VSX. 06 Twenty new W Ursae Majoris-type eclipsing binaries Credit: Justin Ng from the Catalina Sky Survey by Stefan Hümmerich, Klaus Bernhard, Gregor Srdoc 16 Nova Delphini 2013: a naked-eye visible flare in A short overview of eclipsing binary northern skies stars and their traditional by Andrey Prokopovich classification scheme is given, which concentrates on W Ursae Majoris On August 14, 2013 a new bright star (WUMa)-type systems. -
Crowd Science: the Organization of Scientific Research in Open ଝ Collaborative Projects
Research Policy 43 (2014) 1–20 Contents lists available at ScienceDirect Research Policy jou rnal homepage: www.elsevier.com/locate/respol Crowd science: The organization of scientific research in open ଝ collaborative projects a,∗ b Chiara Franzoni , Henry Sauermann a Department of Management, Economics and Industrial Engineering (DIG), Politecnico di Milano, P. Leonardo da Vinci 32, Milan 20133, Italy b Georgia Institute of Technology, Scheller College of Business, 800 W. Peachtree St., Atlanta, GA 30308, USA a r t a b i s c l e i n f o t r a c t Article history: A growing amount of scientific research is done in an open collaborative fashion, in projects sometimes Received 15 November 2012 referred to as “crowd science”, “citizen science”, or “networked science”. This paper seeks to gain a more Received in revised form 12 July 2013 systematic understanding of crowd science and to provide scholars with a conceptual framework and Accepted 13 July 2013 an agenda for future research. First, we briefly present three case examples that span different fields Available online 14 August 2013 of science and illustrate the heterogeneity concerning what crowd science projects do and how they are organized. Second, we identify two fundamental elements that characterize crowd science projects Keywords: – open participation and open sharing of intermediate inputs – and distinguish crowd science from Crowd science other knowledge production regimes such as innovation contests or traditional “Mertonian” science. Citizen science Crowdsourcing Third, we explore potential knowledge-related and motivational benefits that crowd science offers over Community-based production alternative organizational modes, and potential challenges it is likely to face. -
Accretion Flows in Nonmagnetic White Dwarf Binaries As Observed in X-Rays
Accretion Flows in Nonmagnetic White Dwarf Binaries as Observed in X-rays Şölen Balmana,< aKadir Has University, Faculty of Engineering and Natural Sciences, Cibali 34083, Istanbul, Turkey ARTICLEINFO ABSTRACT Keywords: Cataclysmic Variables (CVs) are compact binaries with white dwarf (WD) primaries. CVs and other cataclysmic variables - accretion, accre- accreting WD binaries (AWBs) are useful laboratories for studying accretion flows, gas dynamics, tion disks - thermal emission - non-thermal outflows, transient outbursts, and explosive nuclear burning under different astrophysical plasma con- emission - white dwarfs - X-rays: bina- ditions. They have been studied over decades and are important for population studies of galactic ries X-ray sources. Recent space- and ground-based high resolution spectral and timing studies, along with recent surveys indicate that we still have observational and theoretical complexities yet to an- swer. I review accretion in nonmagnetic AWBs in the light of X-ray observations. I present X-ray diagnostics of accretion in dwarf novae and the disk outbursts, the nova-like systems, and the state of the research on the disk winds and outflows in the nonmagnetic CVs together with comparisons and relations to classical and recurrent nova systems, AM CVns and Symbiotic systems. I discuss how the advective hot accretion flows (ADAF-like) in the inner regions of accretion disks (merged with boundary layer zones) in nonmagnetic CVs explain most of the discrepancies and complexities that have been encountered in the X-ray observations. I stress how flickering variability studies from optical to X-rays can be probes to determine accretion history and disk structure together with how the temporal and spectral variability of CVs are related to that of LMXBs and AGNs. -
Refereed Publications That Name
59 Refereed Publications Since 2011 with Named Co-Authors who are NASA Citizen Scientists Compiled by Marc Kuchner February 2021 Authors in bold are citizen scientists. Aurorasaurus Semeter, J., Hunnekuhl, M., MacDonald, E., Hirsch, M., Zeller, N., Chernenkoff, A., & Wang, J. (2020). The mysterious green streaks below STEVE. AGU Advances, 1, e2020AV000183. https://doi.org/10.1029/2020AV000183 Hunnekuhl, M., & MacDonald, E. (2020). Early ground‐based work by auroral pioneer Carl Størmer on the high‐altitude detached subauroral arcs now known as “STEVE”. Space Weather, 18, e2019SW002384. https://doi.org/10.1029/2019SW002384 S. B. Mende. B. J. Harding, & C. Turner. “Subauroral Green STEVE Arcs: Evidence for Low- Energy Excitation” Geophysical Research Letters, Volume 46, Issue 24, Pages 14256-14262 (2019) http://doi.org/10.1029/2019GL086145 S. B. Mende. & C. Turner. “Color Ratios of Subauroral (STEVE) Arcs” Journal of Geophysical Research (Space Physics),Volume 124, Issue 7, Pages 5945-5955 (2019) http://doi.org/10.1029/2019JA026851 Y. Nishimura, Y., B, Gallardo-Lacourt, B., Y, Zou, E. Mishin, D.J. Knudsen, E. F. Donovan, V. Angelopoulos, R. Raybell, “Magnetospheric Signatures of STEVE: Implications for the Magnetospheric Energy Source and Interhemispheric Conjugacy” Geophysical Research Letters, Volume 46, Issue 11, Pages 5637-5644 (2019) Elizabeth A. MacDonald, Eric Donovan, Yukitoshi Nishimura, Nathan A. Case, D. Megan Gillies, Bea Gallardo-Lacourt, William E. Archer, Emma L. Spanswick, Notanee Bourassa, Martin Connors, Matthew Heavner, Brian Jackel, Burcu Kosar, David J. Knudsen, Chris Ratzlaff and Ian Schofield, “New science in plain sight: Citizen scientists lead to the discovery of optical structure in the upper atmosphere” Science Advances, vol. -
Správa O Činnosti Organizácie SAV Za Rok 2017
Astronomický ústav SAV Správa o činnosti organizácie SAV za rok 2017 Tatranská Lomnica január 2018 Obsah osnovy Správy o činnosti organizácie SAV za rok 2017 1. Základné údaje o organizácii 2. Vedecká činnosť 3. Doktorandské štúdium, iná pedagogická činnosť a budovanie ľudských zdrojov pre vedu a techniku 4. Medzinárodná vedecká spolupráca 5. Vedná politika 6. Spolupráca s VŠ a inými subjektmi v oblasti vedy a techniky 7. Spolupráca s aplikačnou a hospodárskou sférou 8. Aktivity pre Národnú radu SR, vládu SR, ústredné orgány štátnej správy SR a iné organizácie 9. Vedecko-organizačné a popularizačné aktivity 10. Činnosť knižnično-informačného pracoviska 11. Aktivity v orgánoch SAV 12. Hospodárenie organizácie 13. Nadácie a fondy pri organizácii SAV 14. Iné významné činnosti organizácie SAV 15. Vyznamenania, ocenenia a ceny udelené organizácii a pracovníkom organizácie SAV 16. Poskytovanie informácií v súlade so zákonom o slobodnom prístupe k informáciám 17. Problémy a podnety pre činnosť SAV PRÍLOHY A Zoznam zamestnancov a doktorandov organizácie k 31.12.2017 B Projekty riešené v organizácii C Publikačná činnosť organizácie D Údaje o pedagogickej činnosti organizácie E Medzinárodná mobilita organizácie F Vedecko-popularizačná činnosť pracovníkov organizácie SAV Správa o činnosti organizácie SAV 1. Základné údaje o organizácii 1.1. Kontaktné údaje Názov: Astronomický ústav SAV Riaditeľ: Mgr. Martin Vaňko, PhD. Zástupca riaditeľa: Mgr. Peter Gömöry, PhD. Vedecký tajomník: Mgr. Marián Jakubík, PhD. Predseda vedeckej rady: RNDr. Luboš Neslušan, CSc. Člen snemu SAV: Mgr. Marián Jakubík, PhD. Adresa: Astronomický ústav SAV, 059 60 Tatranská Lomnica http://www.ta3.sk Tel.: 052/7879111 Fax: 052/4467656 E-mail: [email protected] Názvy a adresy detašovaných pracovísk: Astronomický ústav - Oddelenie medziplanetárnej hmoty Dúbravská cesta 9, 845 04 Bratislava Vedúci detašovaných pracovísk: Astronomický ústav - Oddelenie medziplanetárnej hmoty prof. -
A Citation Study of Citizen Science Projects in Space Science and Astronomy
Odenwald, S. 2018. A Citation Study of Citizen Science Projects in Space Science and Astronomy. Citizen Science: Theory and Practice, 3(2): 5, pp. 1–11. DOI: https://doi.org/10.5334/cstp.152 RESEARCH PAPER A Citation Study of Citizen Science Projects in Space Science and Astronomy Sten Odenwald This paper presents a citation study of 143 publications in refereed journals resulting from 23 citizen science (CS) projects in space science and astronomy. The projects generated a median of two papers during their average of six years of operation. The 143 papers produced 4,515 citations for a median of 10 citations/paper. These papers were compared to a uniform group of papers published in the year 2000 in refereed space science journals. The CS papers have an average annual peak citation rate that is about four times the average of the year-2000 sample. The CS citation history profiles peak within 3 years after paper publication but decline thereafter at a faster pace than the average paper published in 2000. This suggests that CS papers “burn brighter” but remain of interest for only half as long as other papers in space science and astronomy. Nevertheless, CS papers compare well with some of the most highly ranked “Top-1000” research papers of the modern era. The proportion of CS papers surpassing 200 citations is one-in-26, which is 40-fold higher than the proportion for the typical paper published in 2000. The study concludes that CS projects are not only as good as conventional non-CS research projects in generating publishable results, but can actually outperform the citation rates of the typical non-CS papers in space science and astronomy. -
CH Cygni II: Optical Flickering from an Unstable Disk
To appear in the Astrophysical Journal A Preprint typeset using L TEX style emulateapj v. 14/09/00 CH CYGNI II: OPTICAL FLICKERING FROM AN UNSTABLE DISK J. L. Sokoloski and S. J. Kenyon Smithsonian Astrophysical Observatory, 60 Garden St., Cambridge, MA 02138 [email protected] To appear in the Astrophysical Journal ABSTRACT CH Cygni began producing rapid, stochastic optical variations with the onset of symbiotic activity in 1963. We use changes in this flickering between 1997 and 2000 to diagnose the state of the accretion disk during this time. In the 1998 high state, the luminosity of the B-band flickering component was typically more than 20 times higher than in the 1997 and 2000 low states. Therefore, the physical process or region that produces the flickering was also primarily responsible for the large optical flux increase in the 1998 high state. Assuming that the rapid, stochastic optical variations in CH Cygni come from the accretion disk, as in cataclysmic variable stars, a change in the accretion rate through the disk led to the 1998 bright state. All flickering disappeared in 1999, when the accreting WD was eclipsed by the red giant orbiting with a period of approximately 14 yr, according to the ephemeris of Hinkle et al. and the interpretation of Eyres et al. We did not find any evidence for periodic or quasi-periodic oscillations in the optical emission from CH Cygni in either the high or low state, and we discuss the implications for magnetic propeller models of this system. As one alternative to propeller models, we propose that the activity in CH Cygni is driven by accretion through a disk with a thermal-viscous instability, similar to the instabilities believed to exist in dwarf novae and suggested for FU Ori pre-main-sequence stars and soft X-ray transients. -
Astronomy and Astrophysics Report for 2016
Astronomy and Astrophysics Report for 2016 Submitted to the Governing Board at its meeting on 1st March 2017 1.Research output and activities The primary research output of the section consists of peer-reviewed publications in the leading astronomical and astrophysical journals. The section has a green open-access publishing policy whereby all publications are placed as preprints on the freely accessible arXiv server. To this end DIAS supports arXiv with a modest financial contribution. During the calendar year seventy three papers were published, or posted as preprints on arXiv, and with at least one co-author from the section as well as six non-refereed papers. Full details can be found in the detailed bibliography at the end of this report (which replaces the former summary text). In some ways what is more interesting than the raw number of papers is the trend over time which shows considerable year on year fluctuations, but no major change over the last decade. Refereed Preprints Non-refereed 160 120 80 40 0 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 Note that pre 2010 preprints were classified as non-refereed and not treated as a separate category. In addition to research papers, talks and conference presentations are an important means of communicating our research to our peers and a useful measure of the esteem in which we are held. During the year the following were delivered. Felix Aharonian: 1. Rome, Italy, workshop “Towards a large field-of-view TeV experiment” (14.01-15.01.2016) Evidence for a PeVatron in the Galactic Center: is it Sgr A*? 2.