DOCSLIB.ORG

Spectrum Formation in Stars with Steady-State Extended Atmospheres

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

ot 9uiiw»». Rational Bureau Admin. Library, t-01 * v, %ferenCg 5^ nc {Q taken fr0iT3 f,:i)rar OCT 2 8 1970 ^ y- NBS SPECIAL PUBLICATION 332 Spectrum Formation in Stars With Steady-State Extended Atmospheres ITED STATES DEPARTMENT OF COMMERCE Maurice H. Stans, Secretary NATIONAL BUREAU OF STANDARDS Lewis M. Branscomb, Director Spectrum Formation in Stars With Steady - State Extended Atmospheres Proceedings of the International Astronomical Union Colloquium No. 2, Commission 36 Munich, Germany, April 16-19, 1969 Edited by H. G. Groth and P. Wellmann Universitats-Sternwarte Munchen Institut fur Astronomie und Astrophysik Miinchen, Germany Publication 332 \) , National Bureau of Standards Special * • » Nat. Bur. Stand. (U.S.), Spec. Publ. 332, 342 pages (August 1970) CODEN: XNBSA Issued August 1970 For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 (Order by SD Catalog No. C13.10:332), Price $1.75 NATIONAL BUREAU OF STANDARD FEB 1 2 19/1 ~< ' GENERAL ABSTRACT r> J Commission 36 of the International Astronomical Union sponsored a symposium on Spectrum Formation in Ex- tended Stellar Atmospheres held 16 - 19 April, 1969. The host was the Observatory of the University of Munich. A major problem is the definition of what is meant by an extended stellar atmosphere. There are intuitive notions in the literature, but the question of specific definitions in various kinds of objects was discussed. Questions of what specifi- cally cause the anomalous extent were largely by- passed. Attention focused mainly on the type spec- trum to be expected in various situations. The spectral features to be expected in both static and dynamic atmospheres, including and excluding depar- tures from LTE, were discussed. The symposium was divided into four sections: A. Type of Problems Which Exist; B. Theoretical Methods for Handling Non-LTE Problems; C. Chromospheres and Coronae of Stars; D. Summary. This volume contains the mms of the formal papers that were presented plus an edited and abridged version of the discussions following each paper. Key words: extended atmospheres; non-LTE; chromo- spheres; coronae; non-classical atmospheres. Foreword The planning of this colloquium on Extended Stellar Atmospheres was carried out by Dr. A. B. Underhill, President of Commission 36, and the Organizing Committee of Commission 36, comprised of Drs. K. H. Bohm, R. Cayrel, J. T. Jefferies, V. V, Ivanov, R. N. Thomas, and S. Ueno in close collaboration with Drs. P. Wellmann and H. Groth whose kind invitation gave rise to the idea. This colloquium is one of a series that have been spon- sored by Commission 36 on problems in stellar atmospheres. The aim of these colloquia has been to hold a working session among a number of people vitally interested in the problem, and to provide an inexpensive and readily accessible volume of the proceedings, which can be used by all inter- ested in the subject, especially students and young researchers. A number of United States fed- eral laboratories having strong programs in astron- omy have been hosts to these colloquia and editors- publishers of the proceedings. These include the National Bureau of Standards through the Joint In- stitute for Laboratory Astrophysics, the Smithson- ian Astrophysical Observatory, and now the Goddard Space Flight Center. These proceedings, published by NBS for JILA, follow the approach explored with the publication of the proceedings of the Symposium on Wolf-Rayet Stars, hosted by JILA in 1968. Dr. R. N. Thomas, aided by Alice Levine , of the JILA staff have provided the link between the formal editors, Drs. Wellmann and Groth, and the NBS pub- lications group, under Betty L. Oberholtzer. The typescript was prepared by Breta Triolo. Lewis M. Branscomb, Director iii : CONTENTS Preface vii Participants viii Part A. TYPE OF PROBLEMS THAT EXIST 1 Chairmen: P. Swings P. Wellmann A. B. Underhill Definition of the Types of Prob- lems that Exist in Steady-state Extended Atmospheres (introductory paper) 3 R. N. Thomas Definition of the Physical Prob- lems Connected with Extended Atmospheres 3 8 K. H. Bohm and Extended Atmospheres of Planetary J. Cassinelli: Nuclei 54 H. Nussbaumer: The N IV X5820 Multiplet in WN Stars 61 R. Grant Athay A Self-Consistent Model Atmosphere and R. C. Program with Applications to Solar Canf ield 01 Resonance Lines 65 Part B. THEORETICAL METHODS FOR HANDLING NON-LTE PROBLEMS 8 5 Chairmen: R . N. Thomas^ A. G. Hearn G. Rybicki Theoretical Methods of Treating Line Formation Problems in Steady- state Extended Atmospheres (intro- ductory paper) 8 7 C. Magnan: Application of Monte Carlo Methods in Transfer Problems 119 W. Kalkofen: Line Formation in Moving Atmo- spheres 120 D. H. Menzel Laser Action in Non-LTE Atmo- spheres 134 H. P. Jones and Line Formation in Multi-Dimen- A. Skumanich: sional Media 138 H. Gerola and The Continuous Spectrum of Hydro- N. Panagia: gen in a Low-Density envelope 171 R. Grant Athay Bandwidth Requirements in Spectral Line Transfer Calculations 1 7 9 I. P. Grant and Comparison of Discrete Space and G. E. Hunt: Differential Equation Methods in Non-LTE Transfer Problems 18 9 T. R. Carson: Coherent Line Formation with Depth Dependent Parameters 226 Part C. CHROMOSPHERES AND CORONAE OF STARS 23 9 Chairmen: j. c. Pecker^ D. G. Hummer F. Praderie What Do We Know Through Spectral Information on Stellar Chromo- spheres and Coronas? (introductory paper) 241 R. N. Thomas What Should We Do To Know More About Chromospheres and Coronae of Stars? (introductory paper) 259 H. G. Groth: Observations of c Aurigae Stars and Their Interpretation 283 P. Wellmann The Ionization in Nova Atmo- spheres 290 v A. H. Vaughan, Jr. Circums tellar Call K lines in G, and A. Skumanich: and M Giants and Supergiants 29 5 R. W. Hillendahl: A Physical Mechanism for the Gen- eration of Extended Stellar Atmo- spheres 300 Part D. SUMMARY 3 21 J. C. Pecker: Concluding Remarks 323 vi . PREFACE This colloquium was one of similar colloquia of Commission 36 held in the past few years. The president of Commission 36, Professor A. B. Underhill, planned this colloquium, while the staff members of the Universitats-Sternwarte Munchen were responsible for the local organization. There was an urgent need to discuss problems connected with the structure of extended atmospheres and line formation in these atmospheres Each session of the colloquium had one or two introductory papers followed by discussion. The number of contributed papers was limited. There was no case where the chairman was forced to cut off the discussion because of lack of time, but there was an important criticism by J. C. Pecker and R. N. Thomas: "This colloquium has absolutely no point, if it is so formal that no one ventures to say anything except the older people who think they know what they are doing anyway. It is very important that the younger people take part in the discussion." When compiling these proceedings we have tried to report the discussion remarks as far as possible, when they were relevant to the problem. The paper by G. Rybicki arrived only as the manuscript of this conference was going to press. We were forced to omit the discussion of this paper from the proceed- ings because the discussion could not be understood without the paper. We are very grateful to Anne B. Underhill for the decision to hold this colloquium at Munich. We thank all participants of the conference for coming to our institute. H. G. Groth P. Wellmann vii PARTICIPANTS R. C. ALTROCK, Sacramento Peak Observatory, Sunspot, New Mexico 88349 R. G. ATHAY, High Altitude Observatory, Boulder, Colorado, 80302 K. H. BOHM, Department of Astronomy, University of Washington, Seattle, Washington 98105 R. C. CANFIELD, Sterrewacht Sonnenborgh, Servaas Bolwerk 13, Utrecht, Netherlands F. CAPUTO, Laboratorio di Astrofisica, Casella Postale 67, 00044 Frascati (Roma), Italia T. R. CARSON, University Observatory, Buchanan Gardens, St. Andrews, Scotalnd, U.K. J. M. le CONTEL, Observatoire de Paris, 61 Avenue e de 1'Observ. Paris 14 , France Y. CUNY, Observatoire de Paris, Section d 'Astro- physique, 92 Meudon, France A. M. DELPLACE, Observatoire de Meudon, Meudon 92, France S. DUMONT, Observatoire de Meudon, 9 2 Meudon, France G. H. ELST, Sterrewacht, Ringlaan 3, Brussel 18, Belgium H. GEROLA, Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales , Depto de Fisica, Buenos Aires, Argentina N. GOKDOGAN, University Obs . Astronomi Kursiisii, Beyazit, Istanbul, Turkey G. GONCZI, Laboratoire d ' Astrophysique , Faculte des Sciences, Av. Valrose, 06 Nice, France I. P. GRANT, Atlas Computer Laboratory, Chilton, Didcot Berkshire, England H. G. GROTH, Universitats-Sternwarte Munchen, 8 Miinchen 80, Scheinerstr . 1 , Germany A. G. HEARN, Culham Laboratory, Abingdon, Berkshire, England R. HERMAN, 7 bis rue Trudon, 9 2 Antony, France T. HIRAYAMA, Tokyo Astr. Obs. Univ. of Tokyo, Mitaka, Tokyo, Japan R. W. HILLENDAHL, Lockheed Palo Alto Research Laboratories 3251 Hanover Street, Palo Alto, California 94304 M. HOTINLI, University Obs. Astronomi Kiirsusu, Beyazit, Istanbul, Turkey L. HOUZIAUX, Department d 'Astrophysique , Faculte des Sciences, Plaine de Nimy, Mons , Belgium D. G. HUMMER, JILA, University of Colorado, Boulder, Colorado 80302 K. HUNGER, Institut fur theoretische Physik, Technische Univ. Berlin, 1 Berlin 10, Ernst- Reuter-Platz , Germany viii G. E. HUNT, Atlas Computer Laboratory, Chilton, Didcot, Berkshire, England W. KALKOFEN, Harvard and Smithsonian Observatories, Cambridge, Massachusetts 02138 H. LAMERS , Sterrewacht Sonnenborgh, Servaas Bolwerk 13, Utrecht, Netherlands A. MARTINI, Laboratorio di Astrofisica, Casella Postale 67, 00044 Frascati , Italy 1 CHR. MAGNAN, Institut d Astrophysique , 98 bis BD e Arago, Paris (14 ) , France D. H. MENZEL, Harvard College Observatory, Cambridge, Massachusetts 02138 D. MUGGLESTONE, Department of Theoretical Physics, University of Queensland, Australia L. NEVEN, Sterrewacht, Ringlaan 3, Brussel 18, Belgium H. NUSSBAUMER, Physics Department, University College, Gower Street, London W.C.I.
Recommended publications
  • Detection and Characterization of Hot Subdwarf Companions of Massive Stars Luqian Wang

    Detection and Characterization of Hot Subdwarf Companions of Massive Stars Luqian Wang

    Georgia State University ScholarWorks @ Georgia State University Physics and Astronomy Dissertations Department of Physics and Astronomy 8-13-2019 Detection And Characterization Of Hot Subdwarf Companions Of Massive Stars Luqian Wang Follow this and additional works at: https://scholarworks.gsu.edu/phy_astr_diss Recommended Citation Wang, Luqian, "Detection And Characterization Of Hot Subdwarf Companions Of Massive Stars." Dissertation, Georgia State University, 2019. https://scholarworks.gsu.edu/phy_astr_diss/119 This Dissertation is brought to you for free and open access by the Department of Physics and Astronomy at ScholarWorks @ Georgia State University. It has been accepted for inclusion in Physics and Astronomy Dissertations by an authorized administrator of ScholarWorks @ Georgia State University. For more information, please contact [email protected]. DETECTION AND CHARACTERIZATION OF HOT SUBDWARF COMPANIONS OF MASSIVE STARS by LUQIAN WANG Under the Direction of Douglas R. Gies, PhD ABSTRACT Massive stars are born in close binaries, and in the course of their evolution, the initially more massive star will grow and begin to transfer mass and angular momentum to the gainer star. The mass donor star will be stripped of its outer envelope, and it will end up as a faint, hot subdwarf star. Here I present a search for the subdwarf stars in Be binary systems using the International Ultraviolet Explorer. Through spectroscopic analysis, I detected the subdwarf star in HR 2142 and 60 Cyg. Further analysis led to the discovery of an additional 12 Be and subdwarf candidate systems. I also investigated the EL CVn binary system, which is the prototype of class of eclipsing binaries that consist of an A- or F-type main sequence star and a low mass subdwarf.
  • A Review on Substellar Objects Below the Deuterium Burning Mass Limit: Planets, Brown Dwarfs Or What?

    A Review on Substellar Objects Below the Deuterium Burning Mass Limit: Planets, Brown Dwarfs Or What?

    geosciences Review A Review on Substellar Objects below the Deuterium Burning Mass Limit: Planets, Brown Dwarfs or What? José A. Caballero Centro de Astrobiología (CSIC-INTA), ESAC, Camino Bajo del Castillo s/n, E-28692 Villanueva de la Cañada, Madrid, Spain; [email protected] Received: 23 August 2018; Accepted: 10 September 2018; Published: 28 September 2018 Abstract: “Free-floating, non-deuterium-burning, substellar objects” are isolated bodies of a few Jupiter masses found in very young open clusters and associations, nearby young moving groups, and in the immediate vicinity of the Sun. They are neither brown dwarfs nor planets. In this paper, their nomenclature, history of discovery, sites of detection, formation mechanisms, and future directions of research are reviewed. Most free-floating, non-deuterium-burning, substellar objects share the same formation mechanism as low-mass stars and brown dwarfs, but there are still a few caveats, such as the value of the opacity mass limit, the minimum mass at which an isolated body can form via turbulent fragmentation from a cloud. The least massive free-floating substellar objects found to date have masses of about 0.004 Msol, but current and future surveys should aim at breaking this record. For that, we may need LSST, Euclid and WFIRST. Keywords: planetary systems; stars: brown dwarfs; stars: low mass; galaxy: solar neighborhood; galaxy: open clusters and associations 1. Introduction I can’t answer why (I’m not a gangstar) But I can tell you how (I’m not a flam star) We were born upside-down (I’m a star’s star) Born the wrong way ’round (I’m not a white star) I’m a blackstar, I’m not a gangstar I’m a blackstar, I’m a blackstar I’m not a pornstar, I’m not a wandering star I’m a blackstar, I’m a blackstar Blackstar, F (2016), David Bowie The tenth star of George van Biesbroeck’s catalogue of high, common, proper motion companions, vB 10, was from the end of the Second World War to the early 1980s, and had an entry on the least massive star known [1–3].
  • 2014 Observers Challenge List

    2014 Observers Challenge List

    2014 TMSP Observer's Challenge Atlas page #s # Object Object Type Common Name RA, DEC Const Mag Mag.2 Size Sep. U2000 PSA 18h31m25s 1 IC 1287 Bright Nebula Scutum 20'.0 295 67 -10°47'45" 18h31m25s SAO 161569 Double Star 5.77 9.31 12.3” -10°47'45" Near center of IC 1287 18h33m28s NGC 6649 Open Cluster 8.9m Integrated 5' -10°24'10" Can be seen in 3/4d FOV with above. Brightest star is 13.2m. Approx 50 stars visible in Binos 18h28m 2 NGC 6633 Open Cluster Ophiuchus 4.6m integrated 27' 205 65 Visible in Binos and is about the size of a full Moon, brightest star is 7.6m +06°34' 17h46m18s 2x diameter of a full Moon. Try to view this cluster with your naked eye, binos, and a small scope. 3 IC 4665 Open Cluster Ophiuchus 4.2m Integrated 60' 203 65 +05º 43' Also check out “Tweedle-dee and Tweedle-dum to the east (IC 4756 and NGC 6633) A loose open cluster with a faint concentration of stars in a rich field, contains about 15-20 stars. 19h53m27s Brightest star is 9.8m, 5 stars 9-11m, remainder about 12-13m. This is a challenge obJect to 4 Harvard 20 Open Cluster Sagitta 7.7m integrated 6' 162 64 +18°19'12" improve your observation skills. Can you locate the miniature coathanger close by at 19h 37m 27s +19d? Constellation star Corona 5 Corona Borealis 55 Trace the 7 stars making up this constellation, observe and list the colors of each star asterism Borealis 15H 32' 55” Theta Corona Borealis Double Star 4.2m 6.6m .97” 55 Theta requires about 200x +31° 21' 32” The direction our Sun travels in our galaxy.
  • Angular Momentum Mixing Chemical Mixing Conclusions Content

    Angular Momentum Mixing Chemical Mixing Conclusions Content

    Be Stars and Rotational Mixing Th. Rivinius, L.R. R´ımulo & A.C. Carciofi With many thanks for discussions to make things clearer to myself to S. Justham, N. Langer, P. Marchant, G. Meynet, F. Schneider European Southern Observatory, Chile IAG, Sao˜ Paulo, Brasil March 21, 2017 Some Be stars. Credit: Robert Gendler via APOD (January 9, 2006) Pleione, Alkyone, Electra, Merope Intro Angular Momentum Mixing Chemical Mixing Conclusions Content 1 Short Introduction to Be Stars 2 Angular Momentum Mixing 3 Chemical Mixing 4 Conclusions Intro Angular Momentum Mixing Chemical Mixing Conclusions Be star classification Definition (Be stars) A non-supergiant B star whose spectrum has, or had at some time, one or more Balmer lines in emission. (Jaschek et al., 1981; Collins, 1987) (Non-sg B star: 3 to 15 solar masses, 10 000 to 28 000 K) Observational corollary (Disk angular momentum) • Disk is rotationally supported (i.e. Keplerian) ¥ Evidence: Spectro-interferometry, spectroscopy of shell stars, time behaviour of perturbed disks Intro Angular Momentum Mixing Chemical Mixing Conclusions Physical properties of classical Be stars Definition (Classical Be stars) • Emission is formed in a disk ¥ Evidence: Interferometry, polarimetry • Disk is created by central star through mass loss ¥ Evidence: Disks come and go in weeks to decades, absence of mass-transferring companion More physical definition, still based on observational properties, but hard to apply. Though necessary to understand physics. Intro Angular Momentum Mixing Chemical Mixing Conclusions Physical properties of classical Be stars Definition (Classical Be stars) • Emission is formed in a disk ¥ Evidence: Interferometry, polarimetry • Disk is created by central star through mass loss ¥ Evidence: Disks come and go in weeks to decades, absence of mass-transferring companion More physical definition, still based on observational properties, but hard to apply.
  • The Discovery of a Shell-Like Event in the O-Type Star HD 120678�,��,��� (Research Note)

    The Discovery of a Shell-Like Event in the O-Type Star HD 120678,, (Research Note)

    A&A 546, A92 (2012) Astronomy DOI: 10.1051/0004-6361/201118725 & c ESO 2012 Astrophysics The discovery of a shell-like event in the O-type star HD 120678,, (Research Note) R. Gamen1,,J.I.Arias2,†,R.H.Barbá2,3,†, N. I. Morrell4,†,N.R.Walborn5,A.Sota6, J. Maíz Apellániz6,‡,andE.J.Alfaro6 1 Instituto de Astrofísica de La Plata (CONICET) and Facultad de Ciencias Astronómicas y Geofísicas, Universidad Nacional de La Plata, Paseo del Bosque s/n, B1900FWA, La Plata, Argentina e-mail: [email protected] 2 Departamento de Física, Universidad de La Serena, Cisternas 1200 Norte, La Serena, Chile 3 Instituto de Ciencias Astronómicas, de la Tierra y del Espacio (ICATE-CONICET), Avda España 1512 Sur, J5402DSP, San Juan, Argentina 4 Las Campanas Observatory, Carnegie Observatories, Casilla 601, La Serena, Chile 5 Space Telescope Science Institute,‡, 3700 San Martin Drive, Baltimore, MD 21218, USA 6 Instituto de Astrofísica de Andalucía-CSIC, Glorieta de la Astronomía s/n, 18008, Granada, Spain Received 22 December 2011 / Accepted 4 September 2012 ABSTRACT Aims. We report the detection of a shell-like event in the Oe-type star HD 120678. Methods. HD 120678 has been intensively observed as part of a high-resolution spectroscopic monitoring program of southern Galactic O stars and Wolf-Rayet stars of the nitrogen sequence. Results. An optical spectrogram of HD 120678 obtained in June 2008 shows strong H and He i absorption lines instead of the double-peaked emission profiles observed both previously and subsequently, as well as a variety of previously undetected absorption features, mainly of O ii,Siiii and Fe iii.
  • Binocular Double Star Logbook

    Binocular Double Star Logbook

    Astronomical League Binocular Double Star Club Logbook 1 Table of Contents Alpha Cassiopeiae 3 14 Canis Minoris Sh 251 (Oph) Psi 1 Piscium* F Hydrae Psi 1 & 2 Draconis* 37 Ceti Iota Cancri* 10 Σ2273 (Dra) Phi Cassiopeiae 27 Hydrae 40 & 41 Draconis* 93 (Rho) & 94 Piscium Tau 1 Hydrae 67 Ophiuchi 17 Chi Ceti 35 & 36 (Zeta) Leonis 39 Draconis 56 Andromedae 4 42 Leonis Minoris Epsilon 1 & 2 Lyrae* (U) 14 Arietis Σ1474 (Hya) Zeta 1 & 2 Lyrae* 59 Andromedae Alpha Ursae Majoris 11 Beta Lyrae* 15 Trianguli Delta Leonis Delta 1 & 2 Lyrae 33 Arietis 83 Leonis Theta Serpentis* 18 19 Tauri Tau Leonis 15 Aquilae 21 & 22 Tauri 5 93 Leonis OΣΣ178 (Aql) Eta Tauri 65 Ursae Majoris 28 Aquilae Phi Tauri 67 Ursae Majoris 12 6 (Alpha) & 8 Vul 62 Tauri 12 Comae Berenices Beta Cygni* Kappa 1 & 2 Tauri 17 Comae Berenices Epsilon Sagittae 19 Theta 1 & 2 Tauri 5 (Kappa) & 6 Draconis 54 Sagittarii 57 Persei 6 32 Camelopardalis* 16 Cygni 88 Tauri Σ1740 (Vir) 57 Aquilae Sigma 1 & 2 Tauri 79 (Zeta) & 80 Ursae Maj* 13 15 Sagittae Tau Tauri 70 Virginis Theta Sagittae 62 Eridani Iota Bootis* O1 (30 & 31) Cyg* 20 Beta Camelopardalis Σ1850 (Boo) 29 Cygni 11 & 12 Camelopardalis 7 Alpha Librae* Alpha 1 & 2 Capricorni* Delta Orionis* Delta Bootis* Beta 1 & 2 Capricorni* 42 & 45 Orionis Mu 1 & 2 Bootis* 14 75 Draconis Theta 2 Orionis* Omega 1 & 2 Scorpii Rho Capricorni Gamma Leporis* Kappa Herculis Omicron Capricorni 21 35 Camelopardalis ?? Nu Scorpii S 752 (Delphinus) 5 Lyncis 8 Nu 1 & 2 Coronae Borealis 48 Cygni Nu Geminorum Rho Ophiuchi 61 Cygni* 20 Geminorum 16 & 17 Draconis* 15 5 (Gamma) & 6 Equulei Zeta Geminorum 36 & 37 Herculis 79 Cygni h 3945 (CMa) Mu 1 & 2 Scorpii Mu Cygni 22 19 Lyncis* Zeta 1 & 2 Scorpii Epsilon Pegasi* Eta Canis Majoris 9 Σ133 (Her) Pi 1 & 2 Pegasi Δ 47 (CMa) 36 Ophiuchi* 33 Pegasi 64 & 65 Geminorum Nu 1 & 2 Draconis* 16 35 Pegasi Knt 4 (Pup) 53 Ophiuchi Delta Cephei* (U) The 28 stars with asterisks are also required for the regular AL Double Star Club.
  • Why Are There Seven Sisters?

    Why Are There Seven Sisters?

    Why are there Seven Sisters? Ray P. Norris1,2 & Barnaby R. M. Norris3,4,5 1 Western Sydney University, Locked Bag 1797, Penrith South, NSW 1797, Australia 2 CSIRO Astronomy & Space Science, PO Box 76, Epping, NSW 1710, Australia 3 Sydney Institute for Astronomy, School of Physics, Physics Road, University of Sydney, NSW 2006, Australia 4 Sydney Astrophotonic Instrumentation Laboratories, Physics Road, University of Sydney, NSW 2006, Australia 5 AAO-USyd, School of Physics, University of Sydney, NSW 2006, Australia Abstract of six stars arranged symmetrically around a seventh, and is There are two puzzles surrounding the therefore probably symbolic rather than a literal picture of Pleiades, or Seven Sisters. First, why are the Pleiades. the mythological stories surrounding them, In Greek mythology, the Seven Sisters are named after typically involving seven young girls be- the Pleiades, who were the daughters of Atlas and Pleione. ing chased by a man associated with the Their father, Atlas, was forced to hold up the sky, and was constellation Orion, so similar in vastly sep- therefore unable to protect his daughters. But to save them arated cultures, such as the Australian Abo- from being raped by Orion the hunter, Zeus transformed them riginal cultures and Greek mythology? Sec- into stars. Orion was the son of Poseidon, the King of the sea, ond, why do most cultures call them “Seven and a Cretan princess. Orion first appears in ancient Greek Sisters" even though most people with good calendars (e.g. Planeaux , 2006), but by the late eighth to eyesight see only six stars? Here we show that both these puzzles may be explained by early seventh centuries BC, he is said to be making unwanted a combination of the great antiquity of the advances on the Pleiades (Hesiod, Works and Days, 618-623).
  • Star Catalog**

    Star Catalog**

    ". -~ STAR CATALOG** A1 ternate~ Bayer Flam- Constel- NOTES NAME Name(s) (Lacaille) steed lation t indicates other names Acamar e 60 Eri Double 81,82 Achernar a Eri "riverls end" Achird f1 24 Cas Acrab Elacrab p 8 Sco Double ~l, ~2 Acrux a Cru double Acubens Sertan a 65 Cnc "claws" of crab Adara e 21 CMa Double Adhafera ~ 36 Leo Adhara Adara e 2 CMa "the Virgins" Agena Hadar 13 Cen "kneell Double Ailkes Alkes, Alkers a 7 Crt Ain e 74 Tau Aladfar rJ 20 Lyr Alamak Almach y 57 And Alaraph Zavijava 13 5 Vir Albali e 2 Aqr "the swallower" Albireo 13 6 Cyg Double, Head of Swan Alchiba Alchita a 1 Crv "the tentll Alcor 9 80 UMa Double with Mizar, lithe test", lithe near oneil, "the Rider (Arabic)11 Alcyone rt 25 Tau Pleiades Aldebaran Palilicium a 87 Tau I'follower of Pleiades", eye of Bull (Double) Great Hexagon Alderamin a 5 Cep "right arm'l Al Dhanab y Gru Aldib Altais 0 57 Ora see Nodus lIt Alfard Cor Hydrae a 30 Hya (Alphard) Alfirk Alphirk ~ 8 Cep "the flock" Algedi Al Giedi a 5,6 Cap Head of Sea Goat? Double see Giedi Prima & Secunda Giedi Algenib )' 88 Peg "wing" (Sometimes C1Per, see Mirfak)t Algieba )' 41 Leo Double "the lion's mane" Algol Gorgona ~ 26 Per Ecl ipsi ng Bi nary liThe Demon Star" (Arabic) Algorab 0 7 Crv Double, faint secondary called "The Raven" Alhajoth Capella a 13 Aur Alhena .y 24 Gem "a mark (on the foot of Pollux)" Alioth .E 77 UMa "the tai 1 of sheep" Alkaid Alcaid " 21 UMa "the Chief" (see also Benetnash) ~;~:: CA-T- I~ Alternate Bayer F1am- Constel- NOTES NAME Name(s) (lacai 11e:) steed lation t indicates other
  • GTO Keypad Manual, V5.001

    GTO Keypad Manual, V5.001

    ASTRO-PHYSICS GTO KEYPAD Version v5.xxx Please read the manual even if you are familiar with previous keypad versions Flash RAM Updates Keypad Java updates can be accomplished through the Internet. Check our web site www.astro-physics.com/software-updates/ November 11, 2020 ASTRO-PHYSICS KEYPAD MANUAL FOR MACH2GTO Version 5.xxx November 11, 2020 ABOUT THIS MANUAL 4 REQUIREMENTS 5 What Mount Control Box Do I Need? 5 Can I Upgrade My Present Keypad? 5 GTO KEYPAD 6 Layout and Buttons of the Keypad 6 Vacuum Fluorescent Display 6 N-S-E-W Directional Buttons 6 STOP Button 6 <PREV and NEXT> Buttons 7 Number Buttons 7 GOTO Button 7 ± Button 7 MENU / ESC Button 7 RECAL and NEXT> Buttons Pressed Simultaneously 7 ENT Button 7 Retractable Hanger 7 Keypad Protector 8 Keypad Care and Warranty 8 Warranty 8 Keypad Battery for 512K Memory Boards 8 Cleaning Red Keypad Display 8 Temperature Ratings 8 Environmental Recommendation 8 GETTING STARTED – DO THIS AT HOME, IF POSSIBLE 9 Set Up your Mount and Cable Connections 9 Gather Basic Information 9 Enter Your Location, Time and Date 9 Set Up Your Mount in the Field 10 Polar Alignment 10 Mach2GTO Daytime Alignment Routine 10 KEYPAD START UP SEQUENCE FOR NEW SETUPS OR SETUP IN NEW LOCATION 11 Assemble Your Mount 11 Startup Sequence 11 Location 11 Select Existing Location 11 Set Up New Location 11 Date and Time 12 Additional Information 12 KEYPAD START UP SEQUENCE FOR MOUNTS USED AT THE SAME LOCATION WITHOUT A COMPUTER 13 KEYPAD START UP SEQUENCE FOR COMPUTER CONTROLLED MOUNTS 14 1 OBJECTS MENU – HAVE SOME FUN!
  • November 2014

    November 2014

    BeSS report – November 2014 Data compiled by Valérie Desnoux Do not miss the new section on the Be projects by Ernst Pollmann here Observateur Nb spec Guarro Fló 21 Sawicki 16 ñ 106 H-alpha spectra acquired Pollmann 12 ñ 56 objects observed ñ 14 observers contributed Sollecchia 11 Berardi 8 The most observed objects were pi Aqr, gam Cas and pleione HOUPERT 7 Li 6 Montigiani Mannucci 6 Bohlsen 5 Leonardi 4 Lester 4 Graham 3 Powles 2 Locke 1 Total général 106 Objects observed Classique ? Herbig pi Aqr HD 237134 lam Eri OT Gem zet Tau HD 19818 HD 19993 HD 37149 IL Cep gam Cas 12 Vul HD 32188 HD 237118 EW Lac HD 14850 V731 Tau omi Aqr SV Cep PLEIONE HD 30677 HD 13867 HD 33599 ups Cyg BG Phe HD 189689 HD 224905 HD 179218 EM* MWC lam Cyg eps Cas HD 26398 HD 237060 V811 Cas V808 Cas 709 RW Per ACHERNAR 10 Cas 228 Eri eps Tuc nu Cyg HD 223044 HD 20899 bet Psc omi And omi Her BD+62 2346 HD 36408 BD+62 11 BD+62 285 IU Aur EE Cep 31 Peg tet Ari HD 232552 HD 42477 V923 Aql Emission increase since last observations Lam Cyg Emission phase restarting Moderate evolutions of H-alpha line HD 232552 Moderate increase of H-alpha line Emission decrease of H-alpha line HD 19818 Low resolution lack of emission in H-alpha line HD 37149 Emission decreasing after stable period HD 37149 Almost no emission in H-alpha line V438 Aur Emission wings below the continuum V447 aur Emission decrease V442 And Emission decrease after outburst Be monitoring projects By Ernst Pollmann ζ Tau Hα Monitoring The present observations shows, that the Hα EW is now growing again, and a new disk is developing.
  • The Pleiades: the Celestial Herd of Ancient Timekeepers

    The Pleiades: the Celestial Herd of Ancient Timekeepers

    The Pleiades: the celestial herd of ancient timekeepers. Amelia Sparavigna Dipartimento di Fisica, Politecnico di Torino C.so Duca degli Abruzzi 24, Torino, Italy Abstract In the ancient Egypt seven goddesses, represented by seven cows, composed the celestial herd that provides the nourishment to her worshippers. This herd is observed in the sky as a group of stars, the Pleiades, close to Aldebaran, the main star in the Taurus constellation. For many ancient populations, Pleiades were relevant stars and their rising was marked as a special time of the year. In this paper, we will discuss the presence of these stars in ancient cultures. Moreover, we will report some results of archeoastronomy on the role for timekeeping of these stars, results which show that for hunter-gatherers at Palaeolithic times, they were linked to the seasonal cycles of aurochs. 1. Introduction Archeoastronomy studies astronomical practices and related mythologies of the ancient cultures, to understand how past peoples observed and used the celestial phenomena and what was the role played by the sky in their cultures. This discipline is then a branch of the cultural astronomy, an interdisciplinary field that relates astronomical phenomena to current and ancient cultures. It must then be distinguished from the history of astronomy, because astronomy is a culturally specific concept and ancient peoples may have been related to the sky in different way [1,2]. Archeoastronomy is considered as a quite new interdisciplinary science, rooted in the Stonehenge studies of 1960s by the astronomer Gerald Hawkins, who tested Stonehenge alignments by computer, and concluded that these stones marked key dates in the megalithic calendar [3].
  • Symposium on Telescope Science

    Symposium on Telescope Science

    Proceedings for the 26th Annual Conference of the Society for Astronomical Sciences Symposium on Telescope Science Editors: Brian D. Warner Jerry Foote David A. Kenyon Dale Mais May 22-24, 2007 Northwoods Resort, Big Bear Lake, CA Reprints of Papers Distribution of reprints of papers by any author of a given paper, either before or after the publication of the proceedings is allowed under the following guidelines. 1. The copyright remains with the author(s). 2. Under no circumstances may anyone other than the author(s) of a paper distribute a reprint without the express written permission of all author(s) of the paper. 3. Limited excerpts may be used in a review of the reprint as long as the inclusion of the excerpts is NOT used to make or imply an endorsement by the Society for Astronomical Sciences of any product or service. Notice The preceding “Reprint of Papers” supersedes the one that appeared in the original print version Disclaimer The acceptance of a paper for the SAS proceedings can not be used to imply or infer an endorsement by the Society for Astronomical Sciences of any product, service, or method mentioned in the paper. Published by the Society for Astronomical Sciences, Inc. First printed: May 2007 ISBN: 0-9714693-6-9 Table of Contents Table of Contents PREFACE 7 CONFERENCE SPONSORS 9 Submitted Papers THE OLIN EGGEN PROJECT ARNE HENDEN 13 AMATEUR AND PROFESSIONAL ASTRONOMER COLLABORATION EXOPLANET RESEARCH PROGRAMS AND TECHNIQUES RON BISSINGER 17 EXOPLANET OBSERVING TIPS BRUCE L. GARY 23 STUDY OF CEPHEID VARIABLES AS A JOINT SPECTROSCOPY PROJECT THOMAS C.