Selected New Results on Pulsating Variable Stars
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
A Hot Subdwarf-White Dwarf Super-Chandrasekhar Candidate
A hot subdwarf–white dwarf super-Chandrasekhar candidate supernova Ia progenitor Ingrid Pelisoli1,2*, P. Neunteufel3, S. Geier1, T. Kupfer4,5, U. Heber6, A. Irrgang6, D. Schneider6, A. Bastian1, J. van Roestel7, V. Schaffenroth1, and B. N. Barlow8 1Institut fur¨ Physik und Astronomie, Universitat¨ Potsdam, Haus 28, Karl-Liebknecht-Str. 24/25, D-14476 Potsdam-Golm, Germany 2Department of Physics, University of Warwick, Coventry, CV4 7AL, UK 3Max Planck Institut fur¨ Astrophysik, Karl-Schwarzschild-Straße 1, 85748 Garching bei Munchen¨ 4Kavli Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106, USA 5Texas Tech University, Department of Physics & Astronomy, Box 41051, 79409, Lubbock, TX, USA 6Dr. Karl Remeis-Observatory & ECAP, Astronomical Institute, Friedrich-Alexander University Erlangen-Nuremberg (FAU), Sternwartstr. 7, 96049 Bamberg, Germany 7Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125, USA 8Department of Physics and Astronomy, High Point University, High Point, NC 27268, USA *[email protected] ABSTRACT Supernova Ia are bright explosive events that can be used to estimate cosmological distances, allowing us to study the expansion of the Universe. They are understood to result from a thermonuclear detonation in a white dwarf that formed from the exhausted core of a star more massive than the Sun. However, the possible progenitor channels leading to an explosion are a long-standing debate, limiting the precision and accuracy of supernova Ia as distance indicators. Here we present HD 265435, a binary system with an orbital period of less than a hundred minutes, consisting of a white dwarf and a hot subdwarf — a stripped core-helium burning star. -
Divinus Lux Observatory Bulletin: Report #28 100 Dave Arnold
Vol. 9 No. 2 April 1, 2013 Journal of Double Star Observations Page Journal of Double Star Observations VOLUME 9 NUMBER 2 April 1, 2013 Inside this issue: Using VizieR/Aladin to Measure Neglected Double Stars 75 Richard Harshaw BN Orionis (TYC 126-0781-1) Duplicity Discovery from an Asteroidal Occultation by (57) Mnemosyne 88 Tony George, Brad Timerson, John Brooks, Steve Conard, Joan Bixby Dunham, David W. Dunham, Robert Jones, Thomas R. Lipka, Wayne Thomas, Wayne H. Warren Jr., Rick Wasson, Jan Wisniewski Study of a New CPM Pair 2Mass 14515781-1619034 96 Israel Tejera Falcón Divinus Lux Observatory Bulletin: Report #28 100 Dave Arnold HJ 4217 - Now a Known Unknown 107 Graeme L. White and Roderick Letchford Double Star Measures Using the Video Drift Method - III 113 Richard L. Nugent, Ernest W. Iverson A New Common Proper Motion Double Star in Corvus 122 Abdul Ahad High Speed Astrometry of STF 2848 With a Luminera Camera and REDUC Software 124 Russell M. Genet TYC 6223-00442-1 Duplicity Discovery from Occultation by (52) Europa 130 Breno Loureiro Giacchini, Brad Timerson, Tony George, Scott Degenhardt, Dave Herald Visual and Photometric Measurements of a Selected Set of Double Stars 135 Nathan Johnson, Jake Shellenberger, Elise Sparks, Douglas Walker A Pixel Correlation Technique for Smaller Telescopes to Measure Doubles 142 E. O. Wiley Double Stars at the IAU GA 2012 153 Brian D. Mason Report on the Maui International Double Star Conference 158 Russell M. Genet International Association of Double Star Observers (IADSO) 170 Vol. 9 No. 2 April 1, 2013 Journal of Double Star Observations Page 75 Using VizieR/Aladin to Measure Neglected Double Stars Richard Harshaw Cave Creek, Arizona [email protected] Abstract: The VizierR service of the Centres de Donnes Astronomiques de Strasbourg (France) offers amateur astronomers a treasure trove of resources, including access to the most current version of the Washington Double Star Catalog (WDS) and links to tens of thousands of digitized sky survey plates via the Aladin Java applet. -
Observing List
day month year Epoch 2000 local clock time: 23.98 Observing List for 23 7 2019 RA DEC alt az Constellation object mag A mag B Separation description hr min deg min 20 50 Andromeda Gamma Andromedae (*266) 2.3 5.5 9.8 yellow & blue green double star 2 3.9 42 19 28 69 Andromeda Pi Andromedae 4.4 8.6 35.9 bright white & faint blue 0 36.9 33 43 30 55 Andromeda STF 79 (Struve) 6 7 7.8 bluish pair 1 0.1 44 42 16 52 Andromeda 59 Andromedae 6.5 7 16.6 neat pair, both greenish blue 2 10.9 39 2 45 67 Andromeda NGC 7662 (The Blue Snowball) planetary nebula, fairly bright & slightly elongated 23 25.9 42 32.1 31 60 Andromeda M31 (Andromeda Galaxy) large sprial arm galaxy like the Milky Way 0 42.7 41 16 31 61 Andromeda M32 satellite galaxy of Andromeda Galaxy 0 42.7 40 52 32 60 Andromeda M110 (NGC205) satellite galaxy of Andromeda Galaxy 0 40.4 41 41 17 55 Andromeda NGC752 large open cluster of 60 stars 1 57.8 37 41 17 48 Andromeda NGC891 edge on galaxy, needle-like in appearance 2 22.6 42 21 45 69 Andromeda NGC7640 elongated galaxy with mottled halo 23 22.1 40 51 46 57 Andromeda NGC7686 open cluster of 20 stars 23 30.2 49 8 30 121 Aquarius 55 Aquarii, Zeta 4.3 4.5 2.1 close, elegant pair of yellow stars 22 28.8 0 -1 12 120 Aquarius 94 Aquarii 5.3 7.3 12.7 pale rose & emerald 23 19.1 -13 28 32 152 Aquarius M72 globular cluster 20 53.5 -12 32 31 151 Aquarius M73 Y-shaped asterism of 4 stars 20 59 -12 38 16 117 Aquarius NGC7606 Galaxy 23 19.1 -8 29 32 149 Aquarius NGC7009 Saturn Neb planetary nebula, large & bright pale green oval 21 4.2 -11 21.8 38 135 -
Ioptron AZ Mount Pro Altazimuth Mount Instruction
® iOptron® AZ Mount ProTM Altazimuth Mount Instruction Manual Product #8900, #8903 and #8920 This product is a precision instrument. Please read the included QSG before assembling the mount. Please read the entire Instruction Manual before operating the mount. If you have any questions please contact us at [email protected] WARNING! NEVER USE A TELESCOPE TO LOOK AT THE SUN WITHOUT A PROPER FILTER! Looking at or near the Sun will cause instant and irreversible damage to your eye. Children should always have adult supervision while observing. 2 Table of Content Table of Content ......................................................................................................................................... 3 1. AZ Mount ProTM Altazimuth Mount Overview...................................................................................... 5 2. AZ Mount ProTM Mount Assembly ........................................................................................................ 6 2.1. Parts List .......................................................................................................................................... 6 2.2. Identification of Parts ....................................................................................................................... 7 2.3. Go2Nova® 8407 Hand Controller .................................................................................................... 8 2.3.1. Key Description ....................................................................................................................... -
Linear Polarization of a Group of Symbiotic Systems?
ASTRONOMY & ASTROPHYSICS AUGUST 2000, PAGE 197 SUPPLEMENT SERIES Astron. Astrophys. Suppl. Ser. 145, 197–214 (2000) Linear polarization of a group of symbiotic systems? E. Brandi1,2,L.G.Garc´ıa1, V. Piirola3,F.Scaltriti4, and C. Quiroga1,5 1 Facultad de Ciencias Astron´omicas y Geof´ısicas, Universidad Nacional de La Plata, 1900 La Plata, Argentina 2 Member of the Carrera del Investigador Cient´ıfico, Comisi´on de Investigaciones Cient´ıficas de la Provincia de Buenos Aires (CIC), Argentina 3 Tuorla Observatory, University of Turku, Finland 4 Osservatorio Astronomico di Torino, Pino Torinese, Italy 5 Fellow of the Consejo Nacional de Investigaciones Cient´ıficas y T´ecnicas (CONICET), Argentina Received February 21; accepted March 23, 2000 Abstract. We report linear polarization measurements of expected that the symbiotic stars should possess a signifi- a set of symbiotic stars, made at several epochs during cant degree of polarization, since most of them present ex- the period 1994-1998. Evidence of intrinsic polarization tended asymmetric atmospheres, circumbinary envelopes is looked for from the wavelength dependence of the po- and/or dusty circumstellar envelopes, disks, etc. The po- larization degree and position angle in UBVRI bands. larization should be variable with time according to the The results have also been analysed to search for tempo- activity of the star or to the orbital motion. The study of ral variability of polarization. Several objects have shown this variability should give a better insight into the enve- a polarization spectrum different from that produced by lope structures or their binary nature. Serkowski (1970) interstellar dust grains and/or polarimetric variations on reported the first polarimetric study of symbiotic stars. -
A Basic Requirement for Studying the Heavens Is Determining Where In
Abasic requirement for studying the heavens is determining where in the sky things are. To specify sky positions, astronomers have developed several coordinate systems. Each uses a coordinate grid projected on to the celestial sphere, in analogy to the geographic coordinate system used on the surface of the Earth. The coordinate systems differ only in their choice of the fundamental plane, which divides the sky into two equal hemispheres along a great circle (the fundamental plane of the geographic system is the Earth's equator) . Each coordinate system is named for its choice of fundamental plane. The equatorial coordinate system is probably the most widely used celestial coordinate system. It is also the one most closely related to the geographic coordinate system, because they use the same fun damental plane and the same poles. The projection of the Earth's equator onto the celestial sphere is called the celestial equator. Similarly, projecting the geographic poles on to the celest ial sphere defines the north and south celestial poles. However, there is an important difference between the equatorial and geographic coordinate systems: the geographic system is fixed to the Earth; it rotates as the Earth does . The equatorial system is fixed to the stars, so it appears to rotate across the sky with the stars, but of course it's really the Earth rotating under the fixed sky. The latitudinal (latitude-like) angle of the equatorial system is called declination (Dec for short) . It measures the angle of an object above or below the celestial equator. The longitud inal angle is called the right ascension (RA for short). -
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. -
Commission G1 Binary and Multiple Star Systems 1
Transactions IAU, Volume XXXIA Reports on Astronomy 2018-2021 c 2021 International Astronomical Union Maria Teresa Lago, ed. DOI: 00.0000/X000000000000000X COMMISSION G1 BINARY AND MULTIPLE STAR SYSTEMS PRESIDENT Virginia Trimble VICE-PRESIDENT Christopher Adam Tout SECRETARY John Southworth ORGANIZING COMMITTEE Scott William Fleming, Ilya Mandel, Brian D. Mason, Terry D. Oswalt, Alexandre Roman-Lopes TRIENNIAL REPORT 2018{2021 1. Activities of IAU Commission G1 during 2018-2021 by Virginia Trimble (President), as transcribed by David Soderblom (Division G President) It has been a very good three years for binary and multiple systems of stars! If you go to the Astrophysics Data System (which we all know and use more often than we are perhaps prepared to admit) and ask it for any author in the period 2018-02 to 2021-02 and then, sequentially, \binary star," \double star," and \multiple system of stars" there comes back (or did on about 10 March 2020, for the three headings) 9,914 papers with 77,340 citations; 2,496 papers with 14,756 citations, and 3,982 papers with 24,069 citations, respectively. Thus if the three were human beings, they would have h indices of 88, 50, and 57 respectively. There is a small catch: the words do not have to be contiguous in the abstract or keywords, they just both have to be there, so a few of the papers retrieved are not even about astronomy. It is a bit like a very earnest, literal-minded dog, who, asked to bring The Times, returns with three discordant watches. The most-cited binary star paper was B.P. -
Reporte Nº 8
REA/BRASIL REDE DE ASTRONOMIA OBSERVACIONAL BRASIL REPORTE Nº 8 OUTUBRO , 1997 REA/Brasil - REPORTE Nº 8 1 EDITORIAL EXPEDIENTE O Reporte nº 8 é uma publicação da REA/Brasil A presente edição do tradicional - Rede de Astronomia Observacional - Brasil, entidade "Reporte" ocorre quando algumas mudanças amadora de ämbito nacional, com sede em São Paulo, Caixa Postal 310, CEP 01050-970 - São Paulo - SP. fundamentais tëm ocorrido em nossa Rede: a mudança Os Reportes são distribuídos aos associados da de nosso nome - de REA para REA/Brasil, para REA/Brasil e a diversas entidades astronömicas caracterizar uma associação de ämbito realmente amadoras e profissionais, no Brasil e países latino- nacional; a proximidade do décimo aniversário de nossa americanos. associação, com mais de vinte mil observações A REA/Brasil é extruturada setorialmente, sendo os seguintes diretores de cada seção observacional: realizadas por nossos observadores e registradas no Estrelas Variáveis: Antonio Padilla Filho (Rio de Banco de Dados; a reestruturação organizacional Janeiro-RJ) recentemente realizada, possibilitando uma Planetas Inferiores: Cláudio Brasil Leitão Jr. (São comunicação mais ágil entre todos os membros; o Paulo - SP) redesenho de nosso Banco de Dados para uma versão Marte: Nelson Falsarella (São José do Rio Preto - SP) Planetas Jovianos: Frederico Luiz Funari (São Paulo mais amigável e acessível a todos;e o uso definitivo - SP) dos meios eletrönicos de comunicação - correio Lunar: Walter José Maluf (Monte Mor - SP) eletrönico e particularmente a Internet, onde a REA/ Cometas: Tasso Augusto Napoleão (São Paulo - SP) Brasil dispõe de um "site" dinämico e atraente para Meteoros: João Ricardo Oliveira Santos (Campinas - todos aqueles interessados em Astronomia amadora SP) Eclipses: Hélio de Carvalho Vital (Rio de Janeiro - RJ) (http://www.geocities.com/CapeCanaveral/9355). -
Gaia Data Release 2 Special Issue
A&A 623, A110 (2019) Astronomy https://doi.org/10.1051/0004-6361/201833304 & © ESO 2019 Astrophysics Gaia Data Release 2 Special issue Gaia Data Release 2 Variable stars in the colour-absolute magnitude diagram?,?? Gaia Collaboration, L. Eyer1, L. Rimoldini2, M. Audard1, R. I. Anderson3,1, K. Nienartowicz2, F. Glass1, O. Marchal4, M. Grenon1, N. Mowlavi1, B. Holl1, G. Clementini5, C. Aerts6,7, T. Mazeh8, D. W. Evans9, L. Szabados10, A. G. A. Brown11, A. Vallenari12, T. Prusti13, J. H. J. de Bruijne13, C. Babusiaux4,14, C. A. L. Bailer-Jones15, M. Biermann16, F. Jansen17, C. Jordi18, S. A. Klioner19, U. Lammers20, L. Lindegren21, X. Luri18, F. Mignard22, C. Panem23, D. Pourbaix24,25, S. Randich26, P. Sartoretti4, H. I. Siddiqui27, C. Soubiran28, F. van Leeuwen9, N. A. Walton9, F. Arenou4, U. Bastian16, M. Cropper29, R. Drimmel30, D. Katz4, M. G. Lattanzi30, J. Bakker20, C. Cacciari5, J. Castañeda18, L. Chaoul23, N. Cheek31, F. De Angeli9, C. Fabricius18, R. Guerra20, E. Masana18, R. Messineo32, P. Panuzzo4, J. Portell18, M. Riello9, G. M. Seabroke29, P. Tanga22, F. Thévenin22, G. Gracia-Abril33,16, G. Comoretto27, M. Garcia-Reinaldos20, D. Teyssier27, M. Altmann16,34, R. Andrae15, I. Bellas-Velidis35, K. Benson29, J. Berthier36, R. Blomme37, P. Burgess9, G. Busso9, B. Carry22,36, A. Cellino30, M. Clotet18, O. Creevey22, M. Davidson38, J. De Ridder6, L. Delchambre39, A. Dell’Oro26, C. Ducourant28, J. Fernández-Hernández40, M. Fouesneau15, Y. Frémat37, L. Galluccio22, M. García-Torres41, J. González-Núñez31,42, J. J. González-Vidal18, E. Gosset39,25, L. P. Guy2,43, J.-L. Halbwachs44, N. C. Hambly38, D. -
A Comprehensive Study of Cepheid Variables in the Andromeda Galaxy Period Distribution, Blending, and Distance Determination
A&A 473, 847–855 (2007) Astronomy DOI: 10.1051/0004-6361:20077960 & c ESO 2007 Astrophysics A comprehensive study of Cepheid variables in the Andromeda galaxy Period distribution, blending, and distance determination F. Vilardell1,C.Jordi1,3, and I. Ribas2,3 1 Departament d’Astronomia i Meteorologia, Universitat de Barcelona, c/ Martí i Franquès, 1, 08028 Barcelona, Spain e-mail: [francesc.vilardell;carme.jordi]@am.ub.es 2 Institut de Ciències de l’Espai-CSIC, Campus UAB, Facultat de Ciències, Torre C5-parell-2a, 08193 Bellaterra, Spain e-mail: [email protected] 3 Institut d’Estudis Espacials de Catalunya (IEEC), Edif. Nexus, c/ Gran Capità, 2-4, 08034 Barcelona, Spain Received 28 May 2007 / Accepted 18 July 2007 ABSTRACT Extragalactic Cepheids are the basic rungs of the cosmic distance scale. They are excellent standard candles, although their lumi- nosities and corresponding distance estimates can be affected by the particular properties of the host galaxy. Therefore, the accurate analysis of the Cepheid population in other galaxies, and notably in the Andromeda galaxy (M 31), is crucial to obtaining reliable distance determinations. We obtained accurate photometry (in B and V passbands) of 416 Cepheids in M 31 over a five year campaign within a survey aimed at the detection of eclipsing binaries. The resulting Cepheid sample is the most complete in M 31 and has almost the same period distribution as the David Dunlap Observatory sample in the Milky Way. The large number of epochs (∼250 per filter) has permitted the characterisation of the pulsation modes of 356 Cepheids, with 281 of them pulsating in the fundamental mode and 75 in the first overtone. -