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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. -
Variable Star Classification and Light Curves Manual
Variable Star Classification and Light Curves An AAVSO course for the Carolyn Hurless Online Institute for Continuing Education in Astronomy (CHOICE) This is copyrighted material meant only for official enrollees in this online course. Do not share this document with others. Please do not quote from it without prior permission from the AAVSO. Table of Contents Course Description and Requirements for Completion Chapter One- 1. Introduction . What are variable stars? . The first known variable stars 2. Variable Star Names . Constellation names . Greek letters (Bayer letters) . GCVS naming scheme . Other naming conventions . Naming variable star types 3. The Main Types of variability Extrinsic . Eclipsing . Rotating . Microlensing Intrinsic . Pulsating . Eruptive . Cataclysmic . X-Ray 4. The Variability Tree Chapter Two- 1. Rotating Variables . The Sun . BY Dra stars . RS CVn stars . Rotating ellipsoidal variables 2. Eclipsing Variables . EA . EB . EW . EP . Roche Lobes 1 Chapter Three- 1. Pulsating Variables . Classical Cepheids . Type II Cepheids . RV Tau stars . Delta Sct stars . RR Lyr stars . Miras . Semi-regular stars 2. Eruptive Variables . Young Stellar Objects . T Tau stars . FUOrs . EXOrs . UXOrs . UV Cet stars . Gamma Cas stars . S Dor stars . R CrB stars Chapter Four- 1. Cataclysmic Variables . Dwarf Novae . Novae . Recurrent Novae . Magnetic CVs . Symbiotic Variables . Supernovae 2. Other Variables . Gamma-Ray Bursters . Active Galactic Nuclei 2 Course Description and Requirements for Completion This course is an overview of the types of variable stars most commonly observed by AAVSO observers. We discuss the physical processes behind what makes each type variable and how this is demonstrated in their light curves. Variable star names and nomenclature are placed in a historical context to aid in understanding today’s classification scheme. -
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). -
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. -
Proquest Dissertations
Low-mass star formation and the initial mass function in young clusters Item Type text; Dissertation-Reproduction (electronic) Authors Luhman, Kevin Lee, 1971- Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 01/10/2021 22:31:04 Link to Item http://hdl.handle.net/10150/288884 INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beginning at the upper left-hand comer and continuing from left to right in equal sections with small overlaps. Each original is also photographed in one exposure and is included in reduced form at the back of the book. Photographs included in the original manuscript have been reproduced xerographically in this copy. -
COMMISSIONS 27 and 42 of the I.A.U. INFORMATION BULLETIN on VARIABLE STARS Nos. 4101{4200 1994 October { 1995 May EDITORS: L. SZ
COMMISSIONS AND OF THE IAU INFORMATION BULLETIN ON VARIABLE STARS Nos Octob er May EDITORS L SZABADOS and K OLAH TECHNICAL EDITOR A HOLL TYPESETTING K ORI KONKOLY OBSERVATORY H BUDAPEST PO Box HUNGARY IBVSogyallakonkolyhu URL httpwwwkonkolyhuIBVSIBVShtml HU ISSN 2 CONTENTS 1994 No page E F GUINAN J J MARSHALL F P MALONEY A New Apsidal Motion Determination For DI Herculis ::::::::::::::::::::::::::::::::::::: D TERRELL D H KAISER D B WILLIAMS A Photometric Campaign on OW Geminorum :::::::::::::::::::::::::::::::::::::::::::: B GUROL Photo electric Photometry of OO Aql :::::::::::::::::::::::: LIU QUINGYAO GU SHENGHONG YANG YULAN WANG BI New Photo electric Light Curves of BL Eridani :::::::::::::::::::::::::::::::::: S Yu MELNIKOV V S SHEVCHENKO K N GRANKIN Eclipsing Binary V CygS Former InsaType Variable :::::::::::::::::::: J A BELMONTE E MICHEL M ALVAREZ S Y JIANG Is Praesep e KW Actually a Delta Scuti Star ::::::::::::::::::::::::::::: V L TOTH Ch M WALMSLEY Water Masers in L :::::::::::::: R L HAWKINS K F DOWNEY Times of Minimum Light for Four Eclipsing of Four Binary Systems :::::::::::::::::::::::::::::::::::::::::: B GUROL S SELAN Photo electric Photometry of the ShortPeriod Eclipsing Binary HW Virginis :::::::::::::::::::::::::::::::::::::::::::::: M P SCHEIBLE E F GUINAN The Sp otted Young Sun HD EK Dra ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::::::: M BOS Photo electric Observations of AB Doradus ::::::::::::::::::::: YULIAN GUO A New VR Cyclic Change of H in Tau :::::::::::::: -
Appendix 1: Telescope Limiting-Magnitude and Resolution
Appendix 1: Telescope Limiting-Magnitude and Resolution Listed below are limiting-magnitudes and resolution values for a variety of common-sized ( SIZE in inches) backyard telescopes in use today, ranging from 2- to 14-in. in aperture. (The 2.4-in. entry is the ubiquitous 60 mm refractor, of which there are perhaps more than any other telescope in the world!) Values for the minimum visual magnitude ( MAG .) listed here are for single stars and are only very approximate, since experienced keen-eyed observers may see as much as a full magnitude fainter under excellent sky conditions. Companions to visual double stars—especially those in close proximity to a bright primary—are typically much more dif fi cult to see than is a star of the same magnitude placed alone in the eye- piece fi eld. Among the many variables involved are light pollution, sky conditions, optical quality, mirror and lens coatings, eyepiece design, obstructed or unob- structed optical system, color (spectral type) of the star, and even the age of the observer. Only a few representative limiting magnitudes are given here (in incre- ments of increasing aperture), as an indication of what an observer might typically expect to see in various sized telescopes. Three different values in arc-seconds are listed for resolution, which are for two stars of equal brightness and of about the sixth magnitude. These fi gures differ signi fi cantly for brighter, fainter and, espe- cially, unequal pairs. DAWES is the value based on Dawes’ Limit ( R = 4.56/A), RAYLEIGH on the Rayleigh Criterion ( R = 5.5/D), and MARKOWITZ on Markowitz’s Limit ( R = 6.0/D). -
Protoplanetary Disks in Multiple Star Systems
Protoplanetary Disks in Multiple Star Systems The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citation Harris, Robert Jason. 2013. Protoplanetary Disks in Multiple Star Systems. Doctoral dissertation, Harvard University. Citable link http://nrs.harvard.edu/urn-3:HUL.InstRepos:11181142 Terms of Use This article was downloaded from Harvard University’s DASH repository, and is made available under the terms and conditions applicable to Other Posted Material, as set forth at http:// nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#LAA c 2013 — Robert J. Harris All rights reserved. Dissertation Advisor: Dr. Sean M. Andrews Robert J. Harris Protoplanetary Disks in Multiple Star Systems Abstract Most stars are born in multiple systems, so the presence of a stellar companion may commonly influence planet formation. Theory indicates that companions may inhibit planet formation in two ways. First, dynamical interactions can tidally truncate circumstellar disks. Truncation reduces disk lifetimes and masses, leaving less time and material for planet formation. Second, these interactions might reduce grain-coagulation efficiency, slowing planet formation in its earliest stages. I present three observational studies investigating these issues. First is a spatially resolved Submillimeter Array (SMA) census of disks in young multiple systems in the Taurus-Auriga star-forming region to study their bulk properties. With this survey, I confirmed that disk lifetimes are preferentially decreased in multiples: single stars have detectable millimeter-wave continuum emission twice as often as components of multiples. I also verified that millimeter luminosity ( disk mass) declines with decreasing stellar ∝ separation. -
B O L E T I N Asociacion a R G En T in a a S T R O N O M
ISSN 0671-328» BOLETIN DE LA ASOCIACION ARGENTINA DE ASTRONOMIA N.*18 * LA PLATA 1980 Con motivo de cumplirse en 1973 medio milenio del nacimiento de Nicolás Copérnico este Boletín 18 de la Asociación Argentina de Astronomía está dedicado a la memoria del huma nista fundador de la astronomía moderna , BOLETIN DE LA ;■ ASOCIACION ARGENTINA DE ASTRONOMIA N.*18 LA PLATA 1980 ASOCIACION ARGENTINA DE ASTRONOMIA La Comisión Directiva lamenta comunicar el deceso del Dr. Carlos J. Lavagnino acaecida el 12 de noviembre de 1976 luego de una dolorosa enfermedad. El Dr. Lavagnino manifestó siempre un profundo inte rés por las actividades de esta Asociación, que lo contara entre sus más antiguos socios. Esa inclinación lo llevó a ser editor de nuestro Boletín en varias ocasiones, ya que consi deraba que defender y mejorar este Boletín —o su muy año rada revista— era, desde su profesión, una de las formas de lograr un beneficio para todos sus colegas que así pueden tener a su alcance un medio natural, seguro y de jerarquía para la publicación de sus trabajos. Si bien la adversidad lo acosó con insistencia en sus últimos tiempos, sobrepuso su entereza e iluminó con tra bajo tan oscuros momentos. Así fue como corrigió esta edi ción en su última prueba dos días antes de su deceso y así fue como él mismo honró su memoria. LA COMISION DIRECTIVA Dr. C. J. Lavagnino La ejecución del presente Boletín se ha visto conside rablemente demorada por múltiples razones, entre ellas la prolongada enfermedad y lamentable deceso de su editor el Dr. -
5-6Index 6 MB
CLEAR SKIES OBSERVING GUIDES 5-6" Carbon Stars 228 Open Clusters 751 Globular Clusters 161 Nebulae 199 Dark Nebulae 139 Planetary Nebulae 105 Supernova Remnants 10 Galaxies 693 Asterisms 65 Other 4 Clear Skies Observing Guides - ©V.A. van Wulfen - clearskies.eu - [email protected] Index ANDROMEDA - the Princess ST Andromedae And CS SU Andromedae And CS VX Andromedae And CS AQ Andromedae And CS CGCS135 And CS UY Andromedae And CS NGC7686 And OC Alessi 22 And OC NGC752 And OC NGC956 And OC NGC7662 - "Blue Snowball Nebula" And PN NGC7640 And Gx NGC404 - "Mirach's Ghost" And Gx NGC891 - "Silver Sliver Galaxy" And Gx Messier 31 (NGC224) - "Andromeda Galaxy" And Gx Messier 32 (NGC221) And Gx Messier 110 (NGC205) And Gx "Golf Putter" And Ast ANTLIA - the Air Pump AB Antliae Ant CS U Antliae Ant CS Turner 5 Ant OC ESO435-09 Ant OC NGC2997 Ant Gx NGC3001 Ant Gx NGC3038 Ant Gx NGC3175 Ant Gx NGC3223 Ant Gx NGC3250 Ant Gx NGC3258 Ant Gx NGC3268 Ant Gx NGC3271 Ant Gx NGC3275 Ant Gx NGC3281 Ant Gx Streicher 8 - "Parabola" Ant Ast APUS - the Bird of Paradise U Apodis Aps CS IC4499 Aps GC NGC6101 Aps GC Henize 2-105 Aps PN Henize 2-131 Aps PN AQUARIUS - the Water Bearer Messier 72 (NGC6981) Aqr GC Messier 2 (NGC7089) Aqr GC NGC7492 Aqr GC NGC7009 - "Saturn Nebula" Aqr PN NGC7293 - "Helix Nebula" Aqr PN NGC7184 Aqr Gx NGC7377 Aqr Gx NGC7392 Aqr Gx NGC7585 (Arp 223) Aqr Gx NGC7606 Aqr Gx NGC7721 Aqr Gx NGC7727 (Arp 222) Aqr Gx NGC7723 Aqr Gx Messier 73 (NGC6994) Aqr Ast 14 Aquarii Group Aqr Ast 5-6" V2.4 Clear Skies Observing Guides - ©V.A. -
Catherine C. Espaillat
Catherine C. Espaillat Curriculum Vitae Department of Astronomy Office: CAS Room 404A Boston University Phone: (617) 358-3441 725 Commonwealth Avenue E-mail: [email protected] Boston, MA 02215 Website: http://sites.bu.edu/cce Education Ph.D., Astronomy & Astrophysics 2009 University of Michigan M.S., Astronomy 2005 University of Michigan B.A., Astronomy 2003 Columbia University Positions Associate Professor 2020 - present Boston University Department of Astronomy Assistant Professor 2013 - 2020 Boston University Department of Astronomy NASA Carl Sagan Postdoctoral Fellow 2012 - 2013 Harvard-Smithsonian Center for Astrophysics NSF Astronomy & Astrophysics Postdoctoral Fellow 2009 - 2012 Harvard-Smithsonian Center for Astrophysics Honors Scialog Fellow 2019 Research Corporation for Science Advancement Kavli Fellow 2016 National Academy of Sciences Sloan Fellow 2016 Alfred P. Sloan Foundation Carl Sagan Fellow 2012 - 2013 NASA Curriculum Vitae 1 Espaillat Astronomy and Astrophysics Postdoctoral Fellow 2009 - 2012 NSF Mellon Mays University Fellow 2001 - 2009 Woodrow Wilson National Fellowship Foundation Rackham Merit Fellow 2003 - 2005 University of Michigan John W. Kluge Scholar 1999 - 2003 Columbia University Teaching AS203, Principles of Astronomy II Spring 2015, 2018, 2019, 2020 Introductory undergraduate-level course for majors. AS850/851, Astrophysics Seminar Fall 2018, Spring 2019 Graduate-level course. AS101, The Solar System Fall 2014, 2015, 2016, 2019 Introductory undergraduate-level course for non-majors. AS725, Gravitational Astrophysics