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Binocular Universe: Northern Exposure
Binocular Universe: Northern Exposure March 2013 Phil Harrington he northern circumpolar sky holds many binocular targets that we can enjoy throughout the year. This month, let's take aim at the constellation Ursa TMinor, the Little Bear. You may know it better as the Little Dipper, an asterism made up of the seven brightest stars in the Little Bear. Above: Winter star map from Star Watch by Phil Harrington. Above: Finder chart for this month's Binocular Universe. Chart adapted from Touring the Universe through Binoculars Atlas (TUBA), www.philharrington.net/tuba.htm Call it what you will, this star group is most famous as the home of the North Star, Polaris [Alpha (α) Ursae Minoris]. Earth's rotational axis is aimed just three- quarters of a degree away from Polaris, causing it to trace out a very tiny circle around that invisible point every 24 hours. The North Celestial Pole is slowly moving closer to Polaris. It will continue to close to within 14 minutes of arc around the year 2105, when it will slowly start to pull away. While Polaris is currently the pole star, the 26,000-year wobble of Earth's axis, called precession, causes the Celestial Pole's aim to trace a 47° circle in the sky. For instance, during the building of the pyramids nearly 4,600 years ago, the North Pole was aimed toward the star Thuban in Draco. Fast forward 5,200 years from now and the pole will be point near Alderamin in Cepheus. Most of us at one time or another have heard someone misspeak by referring to Polaris as the brightest star in the night sky. -
The Planisphere of the Heavens
The Planisphere of the Heavens by Steven E. Behrmann Book V Copyright© by Steven E. Behrmann All rights reserved 2010 First Draft (Sunnyside Edition) Dedication: This book is dedicated to my blessed little son, Jonathan William Edward, to whom I hope to teach the names of the stars. Table of Contents A Planisphere of the Heavens .......................................................... 12 The Signs of the Seasons ................................................................. 15 The Virgin (Virgo) ........................................................................... 24 Virgo ............................................................................................ 25 Coma ............................................................................................ 27 The Centaur .................................................................................. 29 Boötes ........................................................................................... 31 The Scales (Libra) ............................................................................ 34 Libra ............................................................................................. 35 The Cross (Crux) .......................................................................... 37 The Victim ................................................................................... 39 The Crown .................................................................................... 41 The Scorpion ................................................................................... -
Enabling Science with Gaia Observations of Naked-Eye Stars
Enabling science with Gaia observations of naked-eye stars J. Sahlmanna,b, J. Mart´ın-Fleitasb,c, A. Morab,c, A. Abreub,d, C. M. Crowleyb,e, E. Jolietb,f aEuropean Space Agency, STScI, 3700 San Martin Drive, Baltimore, MD 21218, USA; bEuropean Space Agency, ESAC, P.O. Box 78, Villanueva de la Canada,˜ 28691 Madrid, Spain; cAurora Technology, Crown Business Centre, Heereweg 345, 2161 CA Lisse, The Netherlands; dElecnor Deimos Space, Ronda de Poniente 19, Ed. Fiteni VI, 28760 Tres Cantos, Madrid, Spain; eHE Space Operations BV, Huygensstraat 44, 2201 DK Noordwijk, The Netherlands; fCalifornia Institute of Technology, Pasadena, CA, 91125, USA ABSTRACT ESA’s Gaia space astrometry mission is performing an all-sky survey of stellar objects. At the beginning of the nominal mission in July 2014, an operation scheme was adopted that enabled Gaia to routinely acquire observations of all stars brighter than the original limit of G∼6, i.e. the naked-eye stars. Here, we describe the current status and extent of those observations and their on-ground processing. We present an overview of the data products generated for G<6 stars and the potential scientific applications. Finally, we discuss how the Gaia survey could be enhanced by further exploiting the techniques we developed. Keywords: Gaia, Astrometry, Proper motion, Parallax, Bright Stars, Extrasolar planets, CCD 1. INTRODUCTION There are about 6000 stars that can be observed with the unaided human eye. Greek astronomer Hipparchus used these stars to define the magnitude system still in use today, in which the faintest stars had an apparent visual magnitude of 6. -
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. -
On the Reduction of Star Places by Bohnenberger's Method
21 2834 22 6. Beispiel. 7 Ziffergruppen. Elliptische Elemente eines Cometen. Comet Ellipse 09902 November 19779 11757 18123 Elliptische Elemente des neuen Cometen : I4449 19250 93260. T = November I 9.7 79 M. Z. Berlin Oppenheim. (D = 117'57' = 181 23 M. Aequ. des Jahresanfangs i= I44 49 q 1.9250 1 = e = 0.9902 Opperikeim. Anmerkung. Das 5. und 6. Beispiel bezieht sich auf die von Dr. S. Oppenheim in A. N. 2692 mitgetheilten parabolischen resp. elliptischen Elemente des Cometen 1881VIII. A. Krzlegcr. On t'he Reduction of Stsr Places by Bohnenberger's Method. By Professor Truman Henry Saford.*) Every astronomer who has had much to do with the Using similar considerations I have been in the habit reduction of star places from one epoch to another is of selecting the epochs for the use of Bohnenberger's for- aware that in case the star be very near the pole, or the mula as follows. epochs very distant, the method invented by Bohnen- We have tables for the secular variation, and for the berger must replace the ordinary employment of annual term multiplied by the third power of the time. While precessions and secular variations. these tables are not quite complete enough for close polar It is easy enough to see that when the product of stars, they are a very great help in checking calculations, the interval by the tangent of the star's declination reaches and it is easy enough to use them or to calculate the terms a certain amount the precession series is no longer con- depending upon the third, and by their variations from year vergent. -
Rocznik Astronomiczny 2002
INSTYTUT GEODEZJI I KARTOGRAFII ROCZNIK IGiK ASTRONOMICZNY 2002NA ROK INSTYTUT GEODEZJI I KARTOGRAFII ROCZNIK ASTRONOMICZNY NA ROK 2002 LVII WARSZAWA 2001 Rada Wydawnicza przy Instytucie Geodezji i Kartografii Adam Linsenbarth (przewodniczący), Andrzej Ciołkosz (zast. przewodniczącego), Teresa Baranowska, Stanisław Białousz (Wydział Geodezji i Kartografii PW), Hanna Ciołkosz (sekretarz), Wojciech Janusz, Jan R. Olędzki (Wydział Geografii i Studiów Regionalnych UW), Andrzej Sas–Uhrynowski, Karol Szeliga, Janusz Zieliński (Centrum Badań Kosmicznych) Redaktor naukowy Rocznika Astronomicznego Jan Kryński Sekretarz: Marcin Sękowski Okładkę projektował Łukasz Żak Adres Redakcji: Instytut Geodezji i Kartografii Warszawa, ul. Jasna 2/4 email: [email protected] http: www.igik.edu.pl ISSN 0209-0341 INSTYTUT GEODEZJI I KARTOGRAFII Arkuszy wydawniczych 24.85. Papier offsetowy kl. III, g 90, 707–500 mm. Do druku od- dano 14.XII.2001 r. Druk ukończono w grudniu 2001 r. na zamówienie ZAGiGS/IGiK/2001 DRUK: INSTYTUT GEODEZJI I KARTOGRAFII — WARSZAWA, ul. Jasna 2/4 SPIS TREŚCI Przedmowa .................................................................................. 5 Skróty stosowane w Roczniku Astronomicznym .............................................. 6 Dni świąteczne, pory roku, stałe precesyjne, obserwatoria astronomiczne ...................... 7 Czas gwiazdowy Greenwich .............................................................. 8÷11 Słońce, współrzędne równikowe, wschody i zachody w Warszawie ........................ 12÷19 Księżyc, współrzędne równikowe, -
Planetary Companions Around the K Giant Stars 11 Ursae Minoris and HD 32518
A&A 505, 1311–1317 (2009) Astronomy DOI: 10.1051/0004-6361/200911702 & c ESO 2009 Astrophysics Planetary companions around the K giant stars 11 Ursae Minoris and HD 32518 M. P. Döllinger1, A. P. Hatzes2, L. Pasquini1, E. W. Guenther2, and M. Hartmann2 1 European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching bei München, Germany e-mail: [email protected] 2 Thüringer Landessternwarte Tautenburg, Sternwarte 5, 07778 Tautenburg, Germany Received 22 January 2009 / Accepted 10 August 2009 ABSTRACT Context. 11 UMi and HD 32518 belong to a sample of 62 K giant stars that has been observed since February 2004 using the 2m Alfred Jensch telescope of the Thüringer Landessternwarte (TLS) to measure precise radial velocities (RVs). Aims. The aim of this survey is to investigate the dependence of planet formation on the mass of the host star by searching for plane- tary companions around intermediate-mass giants. Methods. An iodine absorption cell was used to obtain accurate RVs for this study. Results. Our measurements reveal that the RVs of 11 UMi show a periodic variation of 516.22 days with a semiamplitude of −1 −7 K = 189.70 m s . An orbital solution yields a mass function of f (m) = (3.608 ± 0.441) × 10 solar masses (M) and an eccentricity of e = 0.083 ± 0.03. The RV curve of HD 32518 shows sinusoidal variations with a period of 157.54 days and a semiamplitude of −1 −8 K = 115.83 m s . An orbital solution yields an eccentricity, e = 0.008 ± 0.03 and a mass function, f (m) = (2.199 ± 0.235) × 10 M. -
Science Academic Standards Over the Course of the Cyclical Review Process and Their Efforts and Input Are Appreciated
SOUTH CAROLINA ACADEMIC STANDARDS AND PERFORMANCE INDICATORS FOR SCIENCE Mick Zais, Ph.D. State Superintendent of Education South Carolina Department of Education Columbia, South Carolina This document approved by Education Oversight Committee and State Board of Education Contents Acknowledgements ........................................................................................................................ iii Introduction .................................................................................................................................... 1 Academic Standards and Performance Indicators for Science Kindergarten .................................................................................................................................... 5 Grade 1 .......................................................................................................................................... 11 Grade 2 .......................................................................................................................................... 18 Grade 3 .......................................................................................................................................... 25 Grade 4 .......................................................................................................................................... 32 Grade 5 .......................................................................................................................................... 39 Grade 6 ......................................................................................................................................... -
Manganese Spread in Ursa Minor As a Proof of Sub-Classes of Type Ia
Astronomy & Astrophysics manuscript no. paperMn6 c ESO 2018 September 22, 2018 Manganese spread in Ursa Minor as a proof of sub-classes of type Ia supernovae G. Cescutti1,3 ⋆ and C. Kobayashi2,3 1 INAF, Osservatorio Astronomico di Trieste, I-34131 Trieste, Italy 2 Centre for Astrophysics Research, School of Physics, Astronomy and Mathematics, University of Hertfordshire, College Lane, Hatfield AL10 9AB, UK 3 BRIDGCE UK Network (www.bridgce.net), UK Received xxxx / Accepted xxxx ABSTRACT Context. Recently, new sub-classes of Type Ia supernovae (SNe Ia) were discovered, including SNe Iax. The suggested progenitors of SNe Iax are relatively massive, possibly hybrid C+O+Ne white dwarfs, which can cause white dwarf winds at low metallicities. There is another class that can potentially occur at low or zero metallicities; sub-Chandrasekhar mass explosions in single and/or double degenerate systems of standard C+O white dwarfs. These explosions have different nucleosynthesis yields compared to the normal, Chandrasekhar mass explosions. Aims. We test these SN Ia channels using their characteristic chemical signatures. Methods. The two sub-classes of SNe Ia are expected to be rarer than normal SNe Ia and do not affect the chemical evolution in the solar neighbourhood; however, because of the shorter delay time and/or weaker metallicity dependence, they could influence the evolution of metal-poor systems. Therefore, we have included both in our stochastic chemical evolution model for the dwarf spheroidal galaxy Ursa Minor. Results. The model predicts a butterfly-shape spread in [Mn/Fe] in the interstellar medium at low metallicity and - at the same time - a decrease of [α/Fe] ratios at lower [Fe/H] than in the solar neighbourhood, both of which are consistent with the observed abundances in stars of Ursa Minor. -
Arxiv:2001.10147V1
Magnetic fields in isolated and interacting white dwarfs Lilia Ferrario1 and Dayal Wickramasinghe2 Mathematical Sciences Institute, The Australian National University, Canberra, ACT 2601, Australia Adela Kawka3 International Centre for Radio Astronomy Research, Curtin University, Perth, WA 6102, Australia Abstract The magnetic white dwarfs (MWDs) are found either isolated or in inter- acting binaries. The isolated MWDs divide into two groups: a high field group (105 − 109 G) comprising some 13 ± 4% of all white dwarfs (WDs), and a low field group (B < 105 G) whose incidence is currently under investigation. The situation may be similar in magnetic binaries because the bright accretion discs in low field systems hide the photosphere of their WDs thus preventing the study of their magnetic fields’ strength and structure. Considerable research has been devoted to the vexed question on the origin of magnetic fields. One hypothesis is that WD magnetic fields are of fossil origin, that is, their progenitors are the magnetic main-sequence Ap/Bp stars and magnetic flux is conserved during their evolution. The other hypothesis is that magnetic fields arise from binary interaction, through differential rotation, during common envelope evolution. If the two stars merge the end product is a single high-field MWD. If close binaries survive and the primary develops a strong field, they may later evolve into the arXiv:2001.10147v1 [astro-ph.SR] 28 Jan 2020 magnetic cataclysmic variables (MCVs). The recently discovered population of hot, carbon-rich WDs exhibiting an incidence of magnetism of up to about 70% and a variability from a few minutes to a couple of days may support the [email protected] [email protected] [email protected] Preprint submitted to Journal of LATEX Templates January 29, 2020 merging binary hypothesis. -
Determination of Stellar Parameters for M-Dwarf Stars: the NIR Approach
Determination of stellar parameters for M-dwarf stars: the NIR approach by Daniel Thaagaard Andreasen A thesis submitted in conformity with the requirements for the degree of Doctor of Philosophy Graduate Department of Departamento de Fisica e Astronomia University of Porto c Copyright 2017 by Daniel Thaagaard Andreasen Dedication To Linnea, Henriette, Rico, and Else For always supporting me ii Acknowledgements When doing a PhD it is important to remember it is more a team effort than the work of an individual. This is something I learned quickly during the last four years. Therefore there are several people I would like to thank. First and most importantly are my two supervisors, Sérgio and Nuno. They were after me in the beginning of my studies because I was too shy to ask for help; something that I quickly learned I needed to do. They always had their door open for me and all my small questions. It goes without saying that I am thankful for all their guidance during my studies. However, what I am most thankful for is the freedom I have had to explorer paths and ideas on my own, and with them safely on the sideline. This sometimes led to failures and dead ends, but it make me grow as a researcher both by learning from my mistake, but also by prioritising my time. When I thank Sérgio and Nuno, my official supervisors, I also have to thank Elisa. She has been my third unofficial supervisor almost from the first day. Although she did not have any experience with NIR spectroscopy, she was never afraid of giving her opinion and trying to help. -
BAV Rundbrief
BAV Rundbrief 55. Jahrgang Nr. 3 (2006) ISSN 0405-5497 W. Braune Liebe BAVer 105 F.-J. Hambsch / D. Husar DK And: Neuklassifizierung als EW Bedeckungs- 106 veränderlicher mittels CCD Beobachtungen K. Häussler Einige besondere Sterne im Sonneberger Feld 67 Oph 112 H.-M. Steinbach UU Bootis 130 K. Häussler Photographische Beobachtungen von wenig bekannten 132 Mirasternen (Teil 6) W. Kriebel AO Dra - GCVS-Periode zu kurz 141 H.-M. Steinbach Mögliche 9,6-Jahre Periode bei RS Oph? 142 W. Braune Wer beobachtet mit: W Ursae Minoris 144 Aus der Literatur W. Grimm Aus den IBVS 147 Aus der BAV BAV-Vorstand Einladung und Programm 21. BAV-Tagung Heidelberg 152 BAV-Vorstand Vorschlag: Helmut Busch Ehrenvorsitzender 156 W. Braune Karl Wälke verstorben 156 G.-U. Flechsig Ehrungen in der BAV - aktuelles Konzept des Vorstandes 157 G.-U. Flechsig BAV-Beobachter-Treffen 2006 in Hartha 158 W. Braune Veränderliche für den kleinen Feldstecher 161 W. Braune Hinweise zum BAV-Forum 163 St. Bakan Später Einstieg in die Veränderlichenbeobachtung 164 Aus der Sektion „Kurzperiodische Pulsationssterne“: A. Paschke RT Equ - wieder einmal 167 A. Paschke Der RRc Stern V2298 Oph 168 Aus der Sektion „Mirasterne - Halb- und Unregelmäßige“: R. Winkler Einstieg in Veränderlichenbeobachtung von Mirasternen 170 F. Vohla Das helle Maximum von Chi Cyg im Sommer 2006 172 Aus der Sektion „Kataklysmische“: Th. Lange Aktivitäten zwischen Januar und Juli 2006 173 W. Braune Grundsätzliche Voreingenommenheit moderner Menschen 178 zu visuellen Beobachtungen? J. Hübscher Umstellung aller BAV-Publikationen auf digitale Gestaltung 179 J. Hübscher / D. Bannuscher Anforderungen an die Gestaltung von Artikeln für den BAV 180 Rundbrief und andere BAV-Publikationen J.