Spectral Line Shapes in Plasmas
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NATURE l DECEl\IBEK 28. 1899 J 1 _;. wh. 1m. of Algol 1$ Persei). followed ll\' no loss of accuracy, and thereft•re their puhlicatio:I 1:; . \'enus. Illuminated portion of <lise = o·873· is In :lccordance with th<: decisions of the Con l(r. 6h. sorn. :'llinimum nf Algol (8 . ference of Superintendents of Ephemeride;; held at _l'aris in 1(). t7h. 17m. to 17h. som. OccultatiOn of a Cancn 18<)6, I he constants of aberration, precession, and nutatron have (mag. 4'3) by the moon. _ . lreen altered from the commencement of 1901' ; but, for the con 20 12h. 46m. to 13h. 46m. Occuliatwn of IL\.C. Yenience of oh<en·ers Hill desirint-: to use the Stnl\·e-l'cter's 4006 (mag. 5 71 by the moon. constants, both been inchulcd in the present tables. 21. 1 1 h. 22m. to 12h. 26m. OccultatH>n of '/ "l'Ot•t:I.AR ,. FOR DECE:l!IIER. · -The issue of \"irnini< (mog. 57) by the moon. l'opu!ar Ash·oiiOIII)' for this month contain>, among much -J? ' ISh 3sm. to I6h. 45•11 . Occuliation cf H . .-\.C. generally interesting matter, two useful :lrticlcs by _Profs. II. C. 4722 mag. 5 ·s). \Yilsun and \V. II. Pickering. The former descnbcs a photo 2(}, 1h. Conjunction of Jupiter and the moon graph of the nebula of Andromeda obtained by at Coodsell (Jupiler z ' 3' i'l.). Observatory, the 8-inch Clarke refractor, wrth an exposure I ;h 40n1. of Jupiter'.; Sat. Ill. of twell'e hours given on three nights. -
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 Axis Is Nearly Perpendicular to the Orbital Plane ; (2) the Sense Is the Same As That of the Revolution ; (3) the Period Is Longer Than That of the Revolution
No. 7.] 247 75. An Explanation of the Periodic Variable Stars. By Kiyotsugu HIRAYAMA, M.I.A. Astronomical Observatory, Azabu, Tokyo. (Comm. July 13, 1931.) The binary hypotheses, initially proposed to explain the periodic variable stars, were defective. The pulsation theory seemed more promising ; but even this is disappointing in explaining the varieties and the minor details, of the phenomena. The following explanation ,1) although qualitative, seems satisfactory for those. The hypothesis is based on the capture theory of the stars,2) recently proposed by the writer, and is inconsistent with the fission theory. Cepheid Variables. The Cepheid variable is supposed to be a contact system of a giant star and a dwarf star which is almost dark. The relative orbit is supposed to be nearly circular, in accordance with the general tendency of the binary stars. For the rotation of the primary, the following qualifications are made : (1) the axis is nearly perpendicular to the orbital plane ; (2) the sense is the same as that of the revolution ; (3) the period is longer than that of the revolution. No assumption is made for the rotation of the companion, although the libration is very probable. Taking as a model, the stars of spherical form of the masses 10 and 1 solar units, and the period of revolution, 0.02 year, the mean distance comes out as 0.16 astronomical unit, and the velocitiesrelative to the centre of gravity, as 22.3 and 223.5 km sec-1. As a consequence of the relative motion of the companion, a trail, or an abrasion, so to speak, is left on the surface of the primary, which may be recovered as the time goes on. -
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. -
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). -
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. -
Milan Dimitrijevic Avgust.Qxd
1. M. Platiša, M. Popović, M. Dimitrijević, N. Konjević: 1975, Z. Fur Natur- forsch. 30a, 212 [A 1].* 1. Griem, H. R.: 1975, Stark Broadening, Adv. Atom. Molec. Phys. 11, 331. 2. Platiša, M., Popović, M. V., Konjević, N.: 1975, Stark broadening of O II and O III lines, Astron. Astrophys. 45, 325. 3. Konjević, N., Wiese, W. L.: 1976, Experimental Stark widths and shifts for non-hydrogenic spectral lines of ionized atoms, J. Phys. Chem. Ref. Data 5, 259. 4. Hey, J. D.: 1977, On the Stark broadening of isolated lines of F (II) and Cl (III) by plasmas, JQSRT 18, 649. 5. Hey, J. D.: 1977, Estimates of Stark broadening of some Ar III and Ar IV lines, JQSRT 17, 729. 6. Hey, J. D.: Breger, P.: 1980, Stark broadening of isolated lines emitted by singly - ionized tin, JQSRT 23, 311. 7. Hey, J. D.: Breger, P.: 1981, Stark broadening of isolated ion lines by plas- mas: Application of theory, in Spectral Line Shapes I, ed. B. Wende, W. de Gruyter, 201. 8. Сыркин, М. И.: 1981, Расчеты электронного уширения спектральных линий в теории оптических свойств плазмы, Опт. Спектроск. 51, 778. 9. Wiese, W. L., Konjević, N.: 1982, Regularities and similarities in plasma broadened spectral line widths (Stark widths), JQSRT 28, 185. 10. Konjević, N., Pittman, T. P.: 1986, Stark broadening of spectral lines of ho- mologous, doubly ionized inert gases, JQSRT 35, 473. 11. Konjević, N., Pittman, T. P.: 1987, Stark broadening of spectral lines of ho- mologous, doubly - ionized inert gases, JQSRT 37, 311. 12. Бабин, С. -
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. -
Lick Observatory Records: Photographs UA.036.Ser.07
http://oac.cdlib.org/findaid/ark:/13030/c81z4932 Online items available Lick Observatory Records: Photographs UA.036.Ser.07 Kate Dundon, Alix Norton, Maureen Carey, Christine Turk, Alex Moore University of California, Santa Cruz 2016 1156 High Street Santa Cruz 95064 [email protected] URL: http://guides.library.ucsc.edu/speccoll Lick Observatory Records: UA.036.Ser.07 1 Photographs UA.036.Ser.07 Contributing Institution: University of California, Santa Cruz Title: Lick Observatory Records: Photographs Creator: Lick Observatory Identifier/Call Number: UA.036.Ser.07 Physical Description: 101.62 Linear Feet127 boxes Date (inclusive): circa 1870-2002 Language of Material: English . https://n2t.net/ark:/38305/f19c6wg4 Conditions Governing Access Collection is open for research. Conditions Governing Use Property rights for this collection reside with the University of California. Literary rights, including copyright, are retained by the creators and their heirs. The publication or use of any work protected by copyright beyond that allowed by fair use for research or educational purposes requires written permission from the copyright owner. Responsibility for obtaining permissions, and for any use rests exclusively with the user. Preferred Citation Lick Observatory Records: Photographs. UA36 Ser.7. Special Collections and Archives, University Library, University of California, Santa Cruz. Alternative Format Available Images from this collection are available through UCSC Library Digital Collections. Historical note These photographs were produced or collected by Lick observatory staff and faculty, as well as UCSC Library personnel. Many of the early photographs of the major instruments and Observatory buildings were taken by Henry E. Matthews, who served as secretary to the Lick Trust during the planning and construction of the Observatory. -
Planets and Exoplanets
NASE Publications Planets and exoplanets Planets and exoplanets Rosa M. Ros, Hans Deeg International Astronomical Union, Technical University of Catalonia (Spain), Instituto de Astrofísica de Canarias and University of La Laguna (Spain) Summary This workshop provides a series of activities to compare the many observed properties (such as size, distances, orbital speeds and escape velocities) of the planets in our Solar System. Each section provides context to various planetary data tables by providing demonstrations or calculations to contrast the properties of the planets, giving the students a concrete sense for what the data mean. At present, several methods are used to find exoplanets, more or less indirectly. It has been possible to detect nearly 4000 planets, and about 500 systems with multiple planets. Objetives - Understand what the numerical values in the Solar Sytem summary data table mean. - Understand the main characteristics of extrasolar planetary systems by comparing their properties to the orbital system of Jupiter and its Galilean satellites. The Solar System By creating scale models of the Solar System, the students will compare the different planetary parameters. To perform these activities, we will use the data in Table 1. Planets Diameter (km) Distance to Sun (km) Sun 1 392 000 Mercury 4 878 57.9 106 Venus 12 180 108.3 106 Earth 12 756 149.7 106 Marte 6 760 228.1 106 Jupiter 142 800 778.7 106 Saturn 120 000 1 430.1 106 Uranus 50 000 2 876.5 106 Neptune 49 000 4 506.6 106 Table 1: Data of the Solar System bodies In all cases, the main goal of the model is to make the data understandable. -
Arxiv:2006.10868V2 [Astro-Ph.SR] 9 Apr 2021 Spain and Institut D’Estudis Espacials De Catalunya (IEEC), C/Gran Capit`A2-4, E-08034 2 Serenelli, Weiss, Aerts Et Al
Noname manuscript No. (will be inserted by the editor) Weighing stars from birth to death: mass determination methods across the HRD Aldo Serenelli · Achim Weiss · Conny Aerts · George C. Angelou · David Baroch · Nate Bastian · Paul G. Beck · Maria Bergemann · Joachim M. Bestenlehner · Ian Czekala · Nancy Elias-Rosa · Ana Escorza · Vincent Van Eylen · Diane K. Feuillet · Davide Gandolfi · Mark Gieles · L´eoGirardi · Yveline Lebreton · Nicolas Lodieu · Marie Martig · Marcelo M. Miller Bertolami · Joey S.G. Mombarg · Juan Carlos Morales · Andr´esMoya · Benard Nsamba · KreˇsimirPavlovski · May G. Pedersen · Ignasi Ribas · Fabian R.N. Schneider · Victor Silva Aguirre · Keivan G. Stassun · Eline Tolstoy · Pier-Emmanuel Tremblay · Konstanze Zwintz Received: date / Accepted: date A. Serenelli Institute of Space Sciences (ICE, CSIC), Carrer de Can Magrans S/N, Bellaterra, E- 08193, Spain and Institut d'Estudis Espacials de Catalunya (IEEC), Carrer Gran Capita 2, Barcelona, E-08034, Spain E-mail: [email protected] A. Weiss Max Planck Institute for Astrophysics, Karl Schwarzschild Str. 1, Garching bei M¨unchen, D-85741, Germany C. Aerts Institute of Astronomy, Department of Physics & Astronomy, KU Leuven, Celestijnenlaan 200 D, 3001 Leuven, Belgium and Department of Astrophysics, IMAPP, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, the Netherlands G.C. Angelou Max Planck Institute for Astrophysics, Karl Schwarzschild Str. 1, Garching bei M¨unchen, D-85741, Germany D. Baroch J. C. Morales I. Ribas Institute of· Space Sciences· (ICE, CSIC), Carrer de Can Magrans S/N, Bellaterra, E-08193, arXiv:2006.10868v2 [astro-ph.SR] 9 Apr 2021 Spain and Institut d'Estudis Espacials de Catalunya (IEEC), C/Gran Capit`a2-4, E-08034 2 Serenelli, Weiss, Aerts et al.