DOCSLIB.ORG

Information Bulletin on Variable Stars

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Information Bulletin on Variable Stars COMMISSIONS AND OF THE I A U INFORMATION BULLETIN ON VARIABLE STARS Nos April November EDITORS L SZABADOS K OLAH TECHNICAL EDITOR A HOLL TYPESETTING MB POCS ADMINISTRATION Zs KOVARI EDITORIAL BOARD E Budding HW Duerb eck EF Guinan P Harmanec chair D Kurtz KC Leung C Maceroni NN Samus advisor C Sterken advisor H BUDAPEST XI I Box HUNGARY URL httpwwwkonkolyhuIBVSIBVShtml HU ISSN 2 IBVS 4701 { 4800 COPYRIGHT NOTICE IBVS is published on b ehalf of the th and nd Commissions of the IAU by the Konkoly Observatory Budap est Hungary Individual issues could b e downloaded for scientic and educational purp oses free of charge Bibliographic information of the recent issues could b e entered to indexing sys tems No IBVS issues may b e stored in a public retrieval system in any form or by any means electronic or otherwise without the prior written p ermission of the publishers Prior written p ermission of the publishers is required for entering IBVS issues to an electronic indexing or bibliographic system to o IBVS 4701 { 4800 3 CONTENTS WOLFGANG MOSCHNER ENRIQUE GARCIAMELENDO GSC A New Variable in the Field of V Cassiop eiae :::::::::: JM GOMEZFORRELLAD E GARCIAMELENDO J GUARROFLO J NOMENTORRES J VIDALSAINZ Observations of Selected HIPPARCOS Variables ::::::::::::::::::::::::::: JM GOMEZFORRELLAD HD a New Low Amplitude Variable Star :::::::::::::::::::::::::: ME VAN DEN ANCKER AW VOLP MR PEREZ D DE WINTER NearIR Photometry and Optical Sp ectroscopy of the Herbig Ae Star AB Au rigae ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::::::::::::: KEVIN KRISCIUNAS AND BRIAN M PATTEN Dor Candidates in the Op en Cluster M :::::::::::::::::::::::::::::::: R HAEFNER V Aql An Eclipsing Classical Nova ::::::::::::::::::::: T KIPPER The Dust Shell Around Sakurais Ob ject :::::::::::::::::::::: JENNWOOD CHEN T MICHAEL CORWIN BV Photometry of SX Phe Blue Stragglers in the Globular Cluster NGC GLENN GOMBERT BD a New UU Herculis Variable ::::::::: PETR MOLIK MIROSLAV BROZ MAREK WOLF CCD Photometry of V Cassiop eiae ::::::::::::::::::::::::::::::::::::: FRANZ AGERER JOACHIM HUBSCHER Photo electric Minima of Selected Eclipsing Binaries :::::::::::::::::::::::: FRANZ AGERER MICHAEL DAHM JOACHIM HUBSCHER Photo electric Minima of Selected Eclipsing Binaries and Maxima of Pulsating Stars ::::::::::::::::::::::::::::::::::::::::::::::::::: :::::::::::::::::: H ROVITHISLIVANIOU A KRANIDIOTIS E FRAGOULOPOULOU N SERGIS P ROVITHIS On the Orbital Period Changes of AK Herculis : RM ROBB DD BALAM AND R GREIMEL Discovery of the Optical RXS J :::::::::::: Variability of the Star GSC T J REYNOLDS J R THORSTENSEN AND N D SHERMAN Variable Stars Near V Aql Aql X ::::::::::::::::::::::::::::::: CHULHEE KIM A Susp ected Variable Ob ject in the Field of C ::::::: R DIETHELM GSC a Newly Discovered Variable Star ::::::::: SV ANTIPIN NA GORYNYA ME SACHKOV NN SAMUS LN BERDNIKOV AS RASTORGOUEV EV GLUSHKOVA The Radial Velocity of Doublemo de Cepheid BD :::::::::::::::: BRIAN A SKIFF Co ordinates and Identications for Sonneb erg Variables I ::::::::::::::::: BRIAN A SKIFF Co ordinates and Identications for Sonneb erg variables II :::::::::::::::: BRIAN A SKIFF Co ordinates and Identications for Sonneb erg variables III :::::::::::::: BRIAN A SKIFF FASTT versus IRAS ::::::::::::::::::::::::::::::::::: BRIAN A SKIFF Co ordinates and Identications for Kuro chkins variables near M ::::::::: 4 IBVS 4701 { 4800 L N BERDNIKOV V V IGNATOVA D G TURNER Photo electric BVI c Observations and New Elements for the Cepheid V Centauri :::::::::::: L N BERDNIKOV D G TURNER Photo electric VI Observations and New Classication for RV Normae :::::: c J VANDENBROERE NSV a Lyrae Type Eclipsing Binary ::::::: T RUSSEVA V V and Four New Variable Stars in the Field of M :::: PRISCILLA J BENSON AND DEMERESE M SALTER GSC A Susp ected New Variable ::::::::::::::::::::::::::::::: SAUL J ADELMAN StromgrenPhotometry of the Be Star CrB ::::::::::::::::::: YURIJ N KRUGLY GSC is a New Variable Star ::::::::::::::: HILMAR W DUERBECK Hipparcos Parallaxes of Cataclysmic Binaries and the Quest for Their Absolute Magnitudes :::::::::::::::::::::::::::::::::: P MERCHANBENITEZ M JURADOVARGAS F SANCHEZBAJO Photometric Observations of NSV ::::::::::::::::::::::::::::::::::: JD FERNIE A Photometric Up date on Coronae Borealis ::::::::::::::: LENNART DAHLMARK New Variable Stars in Andromeda and Cassiop eia PK ABOLMASOV SYU SHUGAROV Discovery of a New Mira Variable ::::::::::::::::::::::::::::::::::::::::: SEI ICHIRO KIYOTA Photometry of the outburst of U Scorpii ::::::: CLAUD H SANDBERG LACY KYLE MARCRUM CAFER IBANOGLU Times of Minima of Eclipsing Binaries ::::::::::::::::::::::::::::::::::::: F J CLARKE T A LISTER CCD Lightcurves and Minima Times of the Eclipsing Binary RZ Cas ::::::: Z KVIZ y M ZEJDA L KOHOUTEK J GRYGAR Times of Minima of Some Southern Eclipsing Binaries ::::::::::::::::::::: IOAN TODORAN RODICA ROMAN RZ Cephei Period Variation :::: LIU YY Photometry of the Scuti Star HR :::::::::::::::::::::::: B HASSFORTHER U BASTIAN IRAS A New Mira Variable ::::::::::::::::::::::::::::::::::: AS MIROSHNICHENKO KS KURATOV TA SHEIKINA DB MUKANOV LS i i a Newly Recognized Classical Be star ::::: V SIMON S SHUGAROV Rise from the Low State of the Binary V Sagittae :::::::::::::::::::::::::: T KATO CCD Photometry of BF Eridani a Lowamplitude Dwarf Nova SEI ICHI YOSHIDA KENICHI KADOTA New Variable Stars Discovered in the MISAO Pro ject I MisVMisV E PORETTI The light curves of SX Phe stars in NGC :::::::::::::: M ZBORIL J BUDAJ Dierential UBV photometry of two CP stars Her and Her :::::::::: J R THORSTENSEN The Sp ectrum Period and Prop er Motion of V Scorpii ::::::::::::::::: ROGER DIETHELM MAREK WOLF CCD Photometry of the Eclipsing Binary V Cygni :::::::::::::::::::: Erratum ::::::::::::::::::::::::::::::::::::::::::::::::::: ::::::::::::::: T PRIBULLA D CHOCHOL S PARIMUCHA Photo electric Minima of Some Eclipsing Systems ::::::::::::::::::::::::::: JM DEPASQUALE JJ BOCHANSKI EF GUINAN Recent Light Curves and Period Study of the Contact Binary W Ursae Ma joris :::::::::::::::::: IBVS 4701 { 4800 5 RONALD G SAMEC NW GOTHARD BC PARKER TW SAVAGE SD ANDERSON DANNY R FAULKNER UBV Observations of the Mass Exchanging SolarType Binary BE Cephei :: RAYMOND H BLOOMER JR ISSA R NGWELE Comments on the Light Curve of V Her :::::::::::::::::::::::::::::::: CLAUD H SANDBERG LACY AND JEFFREY A SABBY Absolute Prop erties of ZZ Ursae Ma joris ::::::::::::::::::::::::::::::::::: P MERCHANBENITEZ M JURADOVARGAS F SANCHEZBAJO NSV an RR Lyrae Type Star in Libra :::::::::::::::::::::::::::::: T KATO P SCHMEER CCD Photometry of the February Outburst of CI Gem ::::::::::::::: PATRICK SCHMEER AND HILMAR W DUERBECK The February Outburst of the Dwarf Nova CI Gem ::::::::::::::::::: HILMAR W DUERBECK PATRICK SCHMEER JOHAN H KNAPEN DON POLLACCO The February Sup eroutburst of the SU UMatype Dwarf Nova CG CMa ::::::::::::::::::::::::::::::::::::::::::::::::::: :: T KATO K MATSUMOTO R STUBBINGS CCD Photometry of the Outburst of CG CMa :::::::::::::::::::::::: T KATO Precise Co ordinates of Variable Stars :::::::::::::::::::::::: T KATO Precise Co ordinates of Variable Stars :::::::::::::::::::::::: T KATO K MATSUMOTO CCD Photometry of the February Sup eroutburst of CY UMa ::::::::: T KATO Precise Co ordinates of Variable Stars :::::::::::::::::::::::: T KATO K MATSUMOTO CCD Observation of the Octob er Sup er outburst of PU Per Conrmation as an SU UMatype Dwarf Nova ::::::::: T KATO D NOGAMI H BABA Cyclic Variability of V Aql :::::::: T KATO K MATSUMOTO CCD Photometry of the December Outburst of AQ Eri ::::::::::::::: T KATO CCD Photometry of the March Outburst of BZ UMa Detec tion of QuasiPeriodic Oscillations ::::::::::::::::::::::::::::::::::::::::: T KATO Orbital Mo dulation During the Standstill of VW Vul :::::::::::: SEI ICHI YOSHIDA KENICHI KADOTA TAICHI KATO New Variable Stars Discovered in the MISAO Pro ject I I MisVMisV ::::::::::: SEI ICHI YOSHIDA KENICHI KADOTA TAICHI KATO New Variable Stars Discovered in the MISAO Pro ject I I I MisVMisV ::::::::::: SV ANTIPIN A New Classical Cepheid in Sagitta :::::::::::::::::::::::: NN SAMUS L HAYTHE S HORNSTEIN LJ JISONNA JR E LU Lost Variables on Nantucket Plates :::::::::::::::::::::::::::::::::::::::: WILLIAM LILLER ALBERT JONES Light Curves for Nova Mus and Nova Oph ::::::::::::::::::::::: T ARENTOFT AND C STERKEN A New Dor Candidate in Crux ::::: T KATO K MATSUMOTO CCD Observation of the November Outburst of V Peg An SU UMa type Dwarf Nova With a Long Orbital Period :::::::::::::::::::::::::::: T KATO M UEMURA R STUBBINGS T WATANABE B MONARD Preoutburst Activity of V Sgr SAX J Possible Existence of Day Period ::::::::::::::::::::::::::::::::::::::::::::::::::: :::::: FRANZ AGERER New Elements and Light Curve of CR Tauri :::::::::::: 6 IBVS 4701 { 4800 N BENNERT I KONIG E MANTHEY H BLEUL K FIEGER M HESS A HOVEST W HOVEST T JURGES J KLEIMANN C KRIEGESKORTE E KRUSCH D MUNSTERMANN D REYMANN K ROSLER M NIELBOCK M POHLEN L SCHMIDTOBREICK C TAPPERT R VANSCHEIDT Dierential Photometry of Susp ected Cataclysmic Variables :::::::::::::::: SEI ICHI YOSHIDA KENICHI KADOTA TAICHI KATO New Variable Stars
Load more

Recommended publications
  • Lurking in the Shadows: Wide-Separation Gas Giants As Tracers of Planet Formation
    Lurking in the Shadows: Wide-Separation Gas Giants as Tracers of Planet Formation Thesis by Marta Levesque Bryan In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy CALIFORNIA INSTITUTE OF TECHNOLOGY Pasadena, California 2018 Defended May 1, 2018 ii © 2018 Marta Levesque Bryan ORCID: [0000-0002-6076-5967] All rights reserved iii ACKNOWLEDGEMENTS First and foremost I would like to thank Heather Knutson, who I had the great privilege of working with as my thesis advisor. Her encouragement, guidance, and perspective helped me navigate many a challenging problem, and my conversations with her were a consistent source of positivity and learning throughout my time at Caltech. I leave graduate school a better scientist and person for having her as a role model. Heather fostered a wonderfully positive and supportive environment for her students, giving us the space to explore and grow - I could not have asked for a better advisor or research experience. I would also like to thank Konstantin Batygin for enthusiastic and illuminating discussions that always left me more excited to explore the result at hand. Thank you as well to Dimitri Mawet for providing both expertise and contagious optimism for some of my latest direct imaging endeavors. Thank you to the rest of my thesis committee, namely Geoff Blake, Evan Kirby, and Chuck Steidel for their support, helpful conversations, and insightful questions. I am grateful to have had the opportunity to collaborate with Brendan Bowler. His talk at Caltech my second year of graduate school introduced me to an unexpected population of massive wide-separation planetary-mass companions, and lead to a long-running collaboration from which several of my thesis projects were born.
    [Show full text]
  • Where Are the Distant Worlds? Star Maps
    W here Are the Distant Worlds? Star Maps Abo ut the Activity Whe re are the distant worlds in the night sky? Use a star map to find constellations and to identify stars with extrasolar planets. (Northern Hemisphere only, naked eye) Topics Covered • How to find Constellations • Where we have found planets around other stars Participants Adults, teens, families with children 8 years and up If a school/youth group, 10 years and older 1 to 4 participants per map Materials Needed Location and Timing • Current month's Star Map for the Use this activity at a star party on a public (included) dark, clear night. Timing depends only • At least one set Planetary on how long you want to observe. Postcards with Key (included) • A small (red) flashlight • (Optional) Print list of Visible Stars with Planets (included) Included in This Packet Page Detailed Activity Description 2 Helpful Hints 4 Background Information 5 Planetary Postcards 7 Key Planetary Postcards 9 Star Maps 20 Visible Stars With Planets 33 © 2008 Astronomical Society of the Pacific www.astrosociety.org Copies for educational purposes are permitted. Additional astronomy activities can be found here: http://nightsky.jpl.nasa.gov Detailed Activity Description Leader’s Role Participants’ Roles (Anticipated) Introduction: To Ask: Who has heard that scientists have found planets around stars other than our own Sun? How many of these stars might you think have been found? Anyone ever see a star that has planets around it? (our own Sun, some may know of other stars) We can’t see the planets around other stars, but we can see the star.
    [Show full text]
  • Staff, Visiting Scientists and Graduate Students at the Pescara Center December 2012 2
    Staff, Visiting Scientists and Graduate Students at the Pescara Center December 2012 2 Contents ICRANet Faculty Staff……………………………………………………………………. p. 17 Adjunct Professors of the Faculty .……………………………………………………… p. 36 Lecturers…………………………………………………………………………………… p. 64 Research Scientists ……………………………………………………………………….. p. 76 Visiting Scientists ………………………………………………………………………... p. 86 IRAP Ph. D. Students ……………………………………………………………………. p. 103 IRAP Ph. D. Erasmus Mundus Students………………………………………………. p. 123 Administrative and Secretarial Staff …………………………………………………… p. 135 3 4 ICRANet Faculty Staff Belinski Vladimir ICRANet Bianco Carlo Luciano University of Rome “Sapienza” and ICRANet Einasto Jaan Tartu Observatory, Estonia Novello Mario Cesare Lattes-ICRANet Chair CBPF, Rio de Janeiro, Brasil Rueda Jorge A. University of Rome “Sapienza” and ICRANet Ruffini Remo University of Rome “Sapienza” and ICRANet Vereshchagin Gregory ICRANet Xue She-Sheng ICRANet 5 Adjunct Professors Of The Faculty Aharonian Felix Albert Benjamin Jegischewitsch Markarjan Chair Dublin Institute for Advanced Studies, Dublin, Ireland Max-Planck-Institut für Kernphysis, Heidelberg, Germany Amati Lorenzo Istituto di Astrofisica Spaziale e Fisica Cosmica, Italy Arnett David Subramanyan Chandrasektar- ICRANet Chair University of Arizona, Tucson, USA Chakrabarti Sandip P. Centre for Space Physics, India Chardonnet Pascal Université de la Savoie, France Chechetkin Valeri Mstislav Vsevolodich Keldysh-ICRANet Chair Keldysh institute for Applied Mathematics Moscow, Russia Damour Thibault Joseph-Louis
    [Show full text]
  • Explore the Universe Observing Certificate Second Edition
    RASC Observing Committee Explore the Universe Observing Certificate Second Edition Explore the Universe Observing Certificate Welcome to the Explore the Universe Observing Certificate Program. This program is designed to provide the observer with a well-rounded introduction to the night sky visible from North America. Using this observing program is an excellent way to gain knowledge and experience in astronomy. Experienced observers find that a planned observing session results in a more satisfying and interesting experience. This program will help introduce you to amateur astronomy and prepare you for other more challenging certificate programs such as the Messier and Finest NGC. The program covers the full range of astronomical objects. Here is a summary: Observing Objective Requirement Available Constellations and Bright Stars 12 24 The Moon 16 32 Solar System 5 10 Deep Sky Objects 12 24 Double Stars 10 20 Total 55 110 In each category a choice of objects is provided so that you can begin the certificate at any time of the year. In order to receive your certificate you need to observe a total of 55 of the 110 objects available. Here is a summary of some of the abbreviations used in this program Instrument V – Visual (unaided eye) B – Binocular T – Telescope V/B - Visual/Binocular B/T - Binocular/Telescope Season Season when the object can be best seen in the evening sky between dusk. and midnight. Objects may also be seen in other seasons. Description Brief description of the target object, its common name and other details. Cons Constellation where object can be found (if applicable) BOG Ref Refers to corresponding references in the RASC’s The Beginner’s Observing Guide highlighting this object.
    [Show full text]
  • Naming the Extrasolar Planets
    Naming the extrasolar planets W. Lyra Max Planck Institute for Astronomy, K¨onigstuhl 17, 69177, Heidelberg, Germany [email protected] Abstract and OGLE-TR-182 b, which does not help educators convey the message that these planets are quite similar to Jupiter. Extrasolar planets are not named and are referred to only In stark contrast, the sentence“planet Apollo is a gas giant by their assigned scientific designation. The reason given like Jupiter” is heavily - yet invisibly - coated with Coper- by the IAU to not name the planets is that it is consid- nicanism. ered impractical as planets are expected to be common. I One reason given by the IAU for not considering naming advance some reasons as to why this logic is flawed, and sug- the extrasolar planets is that it is a task deemed impractical. gest names for the 403 extrasolar planet candidates known One source is quoted as having said “if planets are found to as of Oct 2009. The names follow a scheme of association occur very frequently in the Universe, a system of individual with the constellation that the host star pertains to, and names for planets might well rapidly be found equally im- therefore are mostly drawn from Roman-Greek mythology. practicable as it is for stars, as planet discoveries progress.” Other mythologies may also be used given that a suitable 1. This leads to a second argument. It is indeed impractical association is established. to name all stars. But some stars are named nonetheless. In fact, all other classes of astronomical bodies are named.
    [Show full text]
  • Cadas Transit Magazine
    TRANSIT The January 2011 Newsletter of NEXT MEETING 14 January 2011, 7.15 pm for a 7.30 pm start Wynyard Planetarium Galaxies with proper names Dave Newton, Sunderland A.S. Contents p.2 Editorial p.2 Letters: I really wish I didn't have to write this…!; Weather predictions Neil Haggath; Keith Johnson Observation reports & planning p.4 Skylights – January 2011 Rob Peeling p.7 Total lunar eclipse, 21 December 2010 (1) Keith Johnson p.8 Total lunar eclipse, 21 December 2010 (2) John McCue General articles p.8 Star of wonder John Crowther p.10 Look again at the Big Dipper! Andy Fleming p.11 Chasing chickens Ray Worthy The Transit quiz p.15 Answers to December's quiz p.16 January's quiz 1 Editorial Rod Cuff December's weather probably sorted out the really hardy observers from the rest. Beautiful as some of the crystal-clear nights were, I used the fact that often the stars appeared to be twinkling wildly to convince myself that seeing would be poor and therefore I needn't feel obliged to stand for hours with snow half-way up my calves and in temperatures of many degrees below freezing. And so I studied last month's lunar eclipse from the relative warmth of a downstairs room with a clear north-west view, knowing that the aforesaid hardy observers would be bound to come up trumps – and so it proved. Take a bow, Keith Johnson and John McCue, whose photographic output appears in this issue. This month there is of course another eclipse, this time a partial solar eclipse visible at sunrise on 4 January.
    [Show full text]
  • Wynyard Planetarium & Observatory a Autumn Observing Notes
    Wynyard Planetarium & Observatory A Autumn Observing Notes Wynyard Planetarium & Observatory PUBLIC OBSERVING – Autumn Tour of the Sky with the Naked Eye CASSIOPEIA Look for the ‘W’ 4 shape 3 Polaris URSA MINOR Notice how the constellations swing around Polaris during the night Pherkad Kochab Is Kochab orange compared 2 to Polaris? Pointers Is Dubhe Dubhe yellowish compared to Merak? 1 Merak THE PLOUGH Figure 1: Sketch of the northern sky in autumn. © Rob Peeling, CaDAS, 2007 version 1.2 Wynyard Planetarium & Observatory PUBLIC OBSERVING – Autumn North 1. On leaving the planetarium, turn around and look northwards over the roof of the building. Close to the horizon is a group of stars like the outline of a saucepan with the handle stretching to your left. This is the Plough (also called the Big Dipper) and is part of the constellation Ursa Major, the Great Bear. The two right-hand stars are called the Pointers. Can you tell that the higher of the two, Dubhe is slightly yellowish compared to the lower, Merak? Check with binoculars. Not all stars are white. The colour shows that Dubhe is cooler than Merak in the same way that red-hot is cooler than white- hot. 2. Use the Pointers to guide you upwards to the next bright star. This is Polaris, the Pole (or North) Star. Note that it is not the brightest star in the sky, a common misconception. Below and to the left are two prominent but fainter stars. These are Kochab and Pherkad, the Guardians of the Pole. Look carefully and you will notice that Kochab is slightly orange when compared to Polaris.
    [Show full text]
  • The Midnight Sky: Familiar Notes on the Stars and Planets, Edward Durkin, July 15, 1869 a Good Way to Start – Find North
    The expression "dog days" refers to the period from July 3 through Aug. 11 when our brightest night star, SIRIUS (aka the dog star), rises in conjunction* with the sun. Conjunction, in astronomy, is defined as the apparent meeting or passing of two celestial bodies. TAAS Fabulous Fifty A program for those new to astronomy Friday Evening, July 20, 2018, 8:00 pm All TAAS and other new and not so new astronomers are welcome. What is the TAAS Fabulous 50 Program? It is a set of 4 meetings spread across a calendar year in which a beginner to astronomy learns to locate 50 of the most prominent night sky objects visible to the naked eye. These include stars, constellations, asterisms, and Messier objects. Methodology 1. Meeting dates for each season in year 2018 Winter Jan 19 Spring Apr 20 Summer Jul 20 Fall Oct 19 2. Locate the brightest and easiest to observe stars and associated constellations 3. Add new prominent constellations for each season Tonight’s Schedule 8:00 pm – We meet inside for a slide presentation overview of the Summer sky. 8:40 pm – View night sky outside The Midnight Sky: Familiar Notes on the Stars and Planets, Edward Durkin, July 15, 1869 A Good Way to Start – Find North Polaris North Star Polaris is about the 50th brightest star. It appears isolated making it easy to identify. Circumpolar Stars Polaris Horizon Line Albuquerque -- 35° N Circumpolar Stars Capella the Goat Star AS THE WORLD TURNS The Circle of Perpetual Apparition for Albuquerque Deneb 1 URSA MINOR 2 3 2 URSA MAJOR & Vega BIG DIPPER 1 3 Draco 4 Camelopardalis 6 4 Deneb 5 CASSIOPEIA 5 6 Cepheus Capella the Goat Star 2 3 1 Draco Ursa Minor Ursa Major 6 Camelopardalis 4 Cassiopeia 5 Cepheus Clock and Calendar A single map of the stars can show the places of the stars at different hours and months of the year in consequence of the earth’s two primary movements: Daily Clock The rotation of the earth on it's own axis amounts to 360 degrees in 24 hours, or 15 degrees per hour (360/24).
    [Show full text]
  • 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).
    [Show full text]
  • Black Hole Spin and Accretion Disk Magnetic Field Strength Estimates
    Draft version October 10, 2019 Typeset using LATEX default style in AASTeX62 Black Hole Spin and Accretion Disk Magnetic Field Strength Estimates for more than 750 AGN and Multiple GBH Ruth A. Daly1,2 — 1Penn State University, Berks Campus, Reading, PA 19608, USA 2Center for Computational Astrophysics, Flatiron Institute, 162 5th Avenue, New York, NY 10010, USA (Received October 10, 2019) Submitted to ApJ ABSTRACT Black hole systems, comprised of a black hole, accretion disk, and collimated outflow are studied here. Three AGN samples including 753 AGN, and 102 measurements of 4 GBH are studied. Applying the theoretical considerations described by Daly (2016), general expressions for the black hole spin function and accretion disk magnetic field strength are presented and applied to obtain the black hole spin function, spin, and accretion disk magnetic field strength in dimensionless and physical units for each source. Relatively high spin values are obtained; spin functions indicate typical spin values of about (0.6 - 1) for the sources. The distribution of accretion disk magnetic field strengths for the three AGN samples are quite broad and have mean values of about 104 G, while those for individual GBH have mean values of about 108 G. Good agreement is found between spin values obtained here and published values obtained with well-established methods; comparisons for 1 GBH and 6 AGN indicate that similar spin values are obtained with independent methods. Black hole spin and disk magnetic field strength demographics are obtained and indicate that black hole spin functions and spins are similar for all of the source types studied including GBH and different categories of AGN.
    [Show full text]
  • Deep-Sky Objects - Autumn Collection an Addition To: Explore the Universe Observing Certificate Third Edition RASC NW Cons Object Mag
    Deep-Sky Objects - Autumn Collection An addition to: Explore the Universe Observing Certificate Third Edition RASC NW Cons Object Mag. PSA Observation Notes: Chart RA Dec Chart 1) Date Time 2 Equipment) 3) Notes # Observing Notes # Sgr M24 The Sagittarias Star Cloud 1. Mag 4.60 RA 18:16.5 Dec -18:50 Distance: 10.0 2. (kly)Star cloud, 95’ x 35’, Small Sagittarius star cloud 3. lies a little over 7 degrees north of teapot lid. Look for 7,8 dark Lanes! Wealth of stars. M24 has dark nebula 67 (interstellar dust – often visible in the infrared (cooler radiation)). Barnard 92 – near the edge northwest – oval in shape. Ref: Celestial Sampler Floating on Cloud 24, p.112 Sgr M18 - 1. RA 18 19.9, Dec -17.08 Distance: 4.9 (kly) 2. Lies less than 1deg above the northern edge of M24. 3 8 Often bypassed by showy neighbours, it is visible as a 67 small hazy patch. Note it's much closer (1/2 the distance) as compared to M24 (10kly) Sgr M17 (Swan Nebula) and M16 – HII region 1. Nebula and Open Clusters 2. 8 67 M17 Wikipedia 3. Ref: Celestial Sampler p. 113 Sct M11 Wild Duck Cluster 5.80 1. 18:51.1 -06:16 Distance: 6.0 (kly) 2. Open cluster, 13’, You can find the “wild duck” cluster, 3. as Admiral Smyth called it, nearly three degrees west of 67 8 Aquila’s beak lying in one of the densest parts of the summer Milky Way: the Scutum Star Cloud. 9 64 10 Vul M27 Dumbbell Nebula 1.
    [Show full text]
  • University of Southampton Research Repository Eprints Soton
    University of Southampton Research Repository ePrints Soton Copyright © and Moral Rights for this thesis are retained by the author and/or other copyright owners. A copy can be downloaded for personal non-commercial research or study, without prior permission or charge. This thesis cannot be reproduced or quoted extensively from without first obtaining permission in writing from the copyright holder/s. The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the copyright holders. When referring to this work, full bibliographic details including the author, title, awarding institution and date of the thesis must be given e.g. AUTHOR (year of submission) "Full thesis title", University of Southampton, name of the University School or Department, PhD Thesis, pagination http://eprints.soton.ac.uk UNIVERSITY OF SOUTHAMPTON The epoch and environmental dependence of radio-loud active galaxy feedback by Judith Ineson Thesis for the degree of Doctor of Philosophy in the FACULTY OF PHYSICAL SCIENCES AND ENGINEERING Department of Physics and Astronomy June 2016 UNIVERSITY OF SOUTHAMPTON ABSTRACT FACULTY OF PHYSICAL SCIENCES AND ENGINEERING Department of Physics and Astronomy Doctor of Philosophy THE EPOCH AND ENVIRONMENTAL DEPENDENCE OF RADIO-LOUD ACTIVE GALAXY FEEDBACK by Judith Ineson This thesis contains the first systematic X-ray investigation of the relationships between the properties of different types of radio-loud AGN and their large-scale environments, using samples at two distinct redshifts to isolate the effects of evolution. I used X-ray ob- servations of the galaxy clusters hosting the radio galaxies to characterise the properties of the environments and compared them with the low-frequency radio properties of the AGN.
    [Show full text]