DOCSLIB.ORG

Theory of Stellar Atmospheres

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Theory of Stellar Atmospheres © Copyright, Princeton University Press. No part of this book may be distributed, posted, or reproduced in any form by digital or mechanical means without prior written permission of the publisher. EXTENDED BIBLIOGRAPHY References [1] D. Abbott. The terminal velocities of stellar winds from early{type stars. Astrophys. J., 225, 893, 1978. [2] D. Abbott. The theory of radiatively driven stellar winds. I. A physical interpretation. Astrophys. J., 242, 1183, 1980. [3] D. Abbott. The theory of radiatively driven stellar winds. II. The line acceleration. Astrophys. J., 259, 282, 1982. [4] D. Abbott. The theory of radiation driven stellar winds and the Wolf{ Rayet phenomenon. In de Loore and Willis [938], page 185. Astrophys. J., 259, 282, 1982. [5] D. Abbott. Current problems of line formation in early{type stars. In Beckman and Crivellari [358], page 279. [6] D. Abbott and P. Conti. Wolf{Rayet stars. Ann. Rev. Astr. Astrophys., 25, 113, 1987. [7] D. Abbott and D. Hummer. Photospheres of hot stars. I. Wind blan- keted model atmospheres. Astrophys. J., 294, 286, 1985. [8] D. Abbott and L. Lucy. Multiline transfer and the dynamics of stellar winds. Astrophys. J., 288, 679, 1985. [9] D. Abbott, C. Telesco, and S. Wolff. 2 to 20 micron observations of mass loss from early{type stars. Astrophys. J., 279, 225, 1984. [10] C. Abia, B. Rebolo, J. Beckman, and L. Crivellari. Abundances of light metals and N I in a sample of disc stars. Astr. Astrophys., 206, 100, 1988. [11] M. Abramowitz and I. Stegun. Handbook of Mathematical Functions. (Washington, DC: U.S. Government Printing Office), 1972. [12] H. Abt. A discussion of spectral classification. Astrophys. J. Suppl., 8, 99, 1963. [13] H. Abt, A. Meinel, W. Morgan, and J. Tapscott. An Atlas of Low{ Dispersion Grating Stellar Spectra. Kitt Peak National Observatory, Steward Observatory, and Yerkes Observatory, 1969. [14] L. Achmad, H. Lamers, and L. Pasquini. Radiation{driven wind models for A, F, and G supergiants. Astr. Astrophys., 320, 196, 1997. 1 For general queries, contact [email protected] © Copyright, Princeton University Press. No part of this book may be distributed, posted, or reproduced in any form by digital or mechanical means without prior written permission of the publisher. [15] T. Adams. The effect of recoil in resonance{line scattering. Astrophys. J., 168, 575, 1971. [16] T. Adams. The escape of resonance{line radiation from extremely opaque media. Astrophys. J., 174, 439, 1972. [17] T. Adams, D. Hummer, and G. Rybicki. Numerical evaluation of the re- 0 distribution function RIIA(x; x ) and the associated scattering integral. J. Quantit. Spectrosc. Radiat. Transf., 11, 1365, 1971. [18] T. Adams and D. Morton. A model atmosphere for a B4 V star with line blanketing. Astrophys. J., 152, 195, 1968. [19] S. Adelman. Recent results on abundance determinations. In Dworetsky et al. [1049], page 27. [20] S. Adelman, F. Kupka, and W. Weiss, editors. Model Atmospheres and Spectrum Synthesis. (San Francisco: Astronomical Society of the Pacific), 1996. [21] S. Adelman, O. Pintado, F. Nieva, K. Rayle, and S. Sanders. On the ef- fective temperatures and surface gravities of superficially normal main{ sequence{band B and A stars. Astr. Astrophys., 392, 1031, 2002. [22] S. Adelman and W. Wiese, editors. Astrophysical Applications of Pow- erful New Databases. (San Francisco: Astronomical Society of the Pa- cific), 1995. [23] C. Aerts and H. Lamers. Maximum mass{loss rates of line{driven winds of massive stars. Astr. Astrophys., 403, 625, 2003. [24] A. Aguilar, A. Covington, R. Hihojosa, I. Phaneuf, C. Alvarez, C. Cis- neros, J. Bozek, I. Dominguez, M. Sant´ama,S. Schlachter, S. Nahar, and B. McLaughlin. Absolute photoionization cross section measure- ments of O II ions from 29.7 eV to 46.2 eV. Astrophys. J. Suppl., 146, 467, 2003. [25] J. Ahlberg, E. Nilson, and J. Walsh. The Theory of Splines and Their Applications. (New York: Academic Press), 1967. [26] A. Ahmad and C. Jeffery. Physical parameters of He{rich subdwarf B stars from medium resolution optical spectroscopy. Astr. Astrophys., 402, 335, 2003. [27] A. Ahmad and C. Jeffery. Physical parameters of He{rich subdwarf B stars from spectral energy distributions. Astr. Astrophys., 413, 323, 2004. [28] A. Ahmad and C. Jeffery. The evolution of He{rich subdwarf B stars. Astrophys. Space Sci., 291, 253, 2004. 2 For general queries, contact [email protected] © Copyright, Princeton University Press. No part of this book may be distributed, posted, or reproduced in any form by digital or mechanical means without prior written permission of the publisher. [29] A. Ahmad and C. Jeffery. Spectroscopic analyses of He{rich subdwarf B stars. In Koester and Moehler [2093], page 291. [30] D. Aitken, M. Barlow, P. Roche, and P. Spenser. 8{13 micron spectra of very late type Wolf{Rayet stars. Mon. Not. Roy. Astr. Soc., 192, 679, 1980. [31] M. Ajmera and K. Chung. Photodetachment of negative hydrogen ions. Phys. Rev. A, 12, 475, 1975. [32] T. Ake and J. Greenstein. Four probable late subdwarfs with extreme metal deficiency. Astrophys. J., 240, 859, 1980. [33] C. Akerman, L. Carigi, P. Nissen, M. Pettini, and M. Asplund. The evolution of the C/O ratio in metal{poor halo stars. Astr. Astro- phys., 414, 931, 2004. [34] B. Alam and S. Ansari. Role of the Gaunt factor in the derivation of dielectronic recombination coefficients. Solar Phys., 96, 219, 1985. [35] B. Albayrak. A spectral analysis of Deneb (A2 Iae). Astr. Astrophys., 364, 237, 2000. [36] B. Alder, S. Fernbach, and M. Rotenberg, editors. Methods in Compu- tational Physics. Volume 7. Astrophysics. (New York: Academic Press), 1967. [37] B. Alder, S. Fernbach, and M. Rotenberg, editors. Methods in Compu- tational Physics. Volume 10. Atomic and Molecular Scattering. (New York: Academic Press), 1971. [38] D. Alexander. Low temperature Rosseland opacity tables. Astrophys. J. Suppl., 29, 363, 1975. [39] D. Alexander. Low temperature Rosseland opacities. In Adelman and Wiese [22], page 63. [40] D. Alexander and J. Ferguson. Low temperature Rosseland opacities. Astrophys. J., 437, 879, 1994. [41] D. Alexander, J. Ferguson, R. Wing, H. Johnson, P. Hauschildt, and F. Allard. Effective temperature scales of red giant stars. In Donahue and Bookbinder [987], page 84. [42] D. Alexander and H. Johnson. Model atmospheres for cool supergiant stars. Astrophys. J., 176, 629, 1972. [43] J. Alexander. The chemical composition and ultraviolet excess of G dwarfs. Mon. Not. Roy. Astr. Soc., 137, 41, 1967. 3 For general queries, contact [email protected] © Copyright, Princeton University Press. No part of this book may be distributed, posted, or reproduced in any form by digital or mechanical means without prior written permission of the publisher. [44] J. Alexander and D. Branch. Problems with strong{line G and K dwarfs. Mon. Not. Roy. Astr. Soc., 164, L19, 1973. [45] F. Allard and P. Hauschildt. Model atmospheres for M subdwarf stars. I. The base model grid. Astrophys. J., 445, 433, 1995. [46] F. Allard, P. Hauschildt, and A. Schweitzer. Spherically Symmetric Model Atmospheres for Low-Mass Pre-Main-Sequence Stars with Effec- tive Temperatures between 2000 and 6800 K. Astrophys. J., 539, 366, 2000. [47] F. Allard and R. Wehrse. Line formation in white dwarf atmospheres. J. Quantit. Spectrosc. Radiat. Transf., 44, 209, 1990. [48] N. Allard, M.{C. Artru, T. Lanz, and M. Le Dourneuf. Compilation of atomic oscillator strengths for C, N, and O ions. The Be isoelectronic sequence (C III, N IV, and O V). Astr. Astrophys. Suppl., 84, 563, 1990. [49] N. Allard and J. Kielkopf. Temperature and density dependence of the Lyα line wing in H{rich white dwarf atmospheres. Astr. Astrophys., 242, 133, 1991. [50] N. Allard and D. Koester. Theoretical profiles of Lyα satellites and application to synthetic spectra of DA white dwarfs. Astr. Astrophys., 258, 464, 1992. [51] N. Allard, D. Koester, N. Feautrier, and A. Spielfiedel. Free{free quasi{ molecular absorption and satellites in Lyα due to collisions with H and H+. Astr. Astrophys. Suppl., 108, 417, 1994. [52] N. Allard, M. Le Dourneuf, M.{C. Artru, and T. Lanz. Compilation of atomic oscillator strengths for C, N, and O ions. II. Addendum for the Be isoelectronic sequence. Astr. Astrophys. Suppl., 91, 399, 1991. [53] C. Allen. Astrophysical Quantities. (London: Athlone Press), 3rd edi- tion, 1973. [54] C. Allende Prieto, M. Asplund, and P. Fabiani Bendicho. Center{to{ limb variation of solar line profiles as a test of NLTE line formation calculations. Astr. Astrophys., 423, 1109, 2004. [55] C. Allende Prieto, M. Asplund, R. Garc´ıa–L´opez, and D. Lambert. Signatures of convection in the spectrum of Procyon: Fundamental pa- rameters and Fe abundance. Astrophys. J., 567, 544, 2002. [56] C. Allende Prieto, P. Barklem, M. Asplund, and B. Ruiz{Cobo. Chemi- cal abundances from inversions of stellar spectra: Analysis of solar{type stars with homogeneous and static model atmospheres. Astrophys. J., 558, 830, 2001. 4 For general queries, contact [email protected] © Copyright, Princeton University Press. No part of this book may be distributed, posted, or reproduced in any form by digital or mechanical means without prior written permission of the publisher. [57] C. Allende Prieto and R. Garc´ıa–L´opez. Fe I line shifts in the optical spectrum of the Sun. Astr. Astrophys. Suppl., 129, 41, 1998. [58] C. Allende Prieto, R. Garc´ıa–L´opez, D. Lambert, and B. Gustafsson. Spectroscopic observations of convective patterns in the atmospheres of metal{poor stars. Astrophys. J., 526, 991, 1999. [59] C. Allende Prieto, R. Garc´ıa–L´opez, D. Lambert, and B. Gustafsson. A consistency test of spectroscopic gravities for late{type stars. Astrophys. J., 527, 879, 1999. [60] C. Allende Prieto, R. Garc´ıaL´opez, D.
Load more

Recommended publications
  • 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.
    [Show full text]
  • 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 ...................................................................................
    [Show full text]
  • Divinus Lux Observatory Bulletin: Report #28 100 Dave Arnold
    Vol. 9 No. 2 April 1, 2013 Journal of Double Star Observations Page Journal of Double Star Observations VOLUME 9 NUMBER 2 April 1, 2013 Inside this issue: Using VizieR/Aladin to Measure Neglected Double Stars 75 Richard Harshaw BN Orionis (TYC 126-0781-1) Duplicity Discovery from an Asteroidal Occultation by (57) Mnemosyne 88 Tony George, Brad Timerson, John Brooks, Steve Conard, Joan Bixby Dunham, David W. Dunham, Robert Jones, Thomas R. Lipka, Wayne Thomas, Wayne H. Warren Jr., Rick Wasson, Jan Wisniewski Study of a New CPM Pair 2Mass 14515781-1619034 96 Israel Tejera Falcón Divinus Lux Observatory Bulletin: Report #28 100 Dave Arnold HJ 4217 - Now a Known Unknown 107 Graeme L. White and Roderick Letchford Double Star Measures Using the Video Drift Method - III 113 Richard L. Nugent, Ernest W. Iverson A New Common Proper Motion Double Star in Corvus 122 Abdul Ahad High Speed Astrometry of STF 2848 With a Luminera Camera and REDUC Software 124 Russell M. Genet TYC 6223-00442-1 Duplicity Discovery from Occultation by (52) Europa 130 Breno Loureiro Giacchini, Brad Timerson, Tony George, Scott Degenhardt, Dave Herald Visual and Photometric Measurements of a Selected Set of Double Stars 135 Nathan Johnson, Jake Shellenberger, Elise Sparks, Douglas Walker A Pixel Correlation Technique for Smaller Telescopes to Measure Doubles 142 E. O. Wiley Double Stars at the IAU GA 2012 153 Brian D. Mason Report on the Maui International Double Star Conference 158 Russell M. Genet International Association of Double Star Observers (IADSO) 170 Vol. 9 No. 2 April 1, 2013 Journal of Double Star Observations Page 75 Using VizieR/Aladin to Measure Neglected Double Stars Richard Harshaw Cave Creek, Arizona [email protected] Abstract: The VizierR service of the Centres de Donnes Astronomiques de Strasbourg (France) offers amateur astronomers a treasure trove of resources, including access to the most current version of the Washington Double Star Catalog (WDS) and links to tens of thousands of digitized sky survey plates via the Aladin Java applet.
    [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]
  • Eps Aur 1982-4 Newsletter No. 6 February 1983
    No. 6 FEBRUARY 1983 Dear Colleagues: Welcome to totality! The eclipse of Episilon Aurigae appears to be close on schedule with first and second contacts occuring in July and December [1982], respectively. The number of reports on photometry and spectroscopy continues to increase, and we are pleased to publish in this issue a significant finding in polarimetry, in addition to other findings. We also provide information presented at recent meetings and in three International Astronomical Union Circulars during January [1983] – see page 2. To improve the efficiency of our operation, we include in this issue a mailing list update response form. We will require return of this form from all interested readers to insure continued receipt of this newsletter. _____________ This Newsletter is (partially) supported by a grant from NASA, administered through the American Astronomical Society. EPS AUR NL 6 1 IAU Circular No. 3759 1983 January 07 ε AURIGAE G. Henson, J. Kemp and D. Kraus, Physics Department, University of Oregon at Eugene, write: "We have observed a sudden change in the polarization of ε Aur between 1982 Nov. 24 and Dec. 9 UT. Measurements in the V filter of normalized Stokes parameters over the interval Aug. 24-Nov. 24 averaged Q = +0.33 +/- 0.03, U = -2.3 +/-0.05. On Dec. 8 and 9 we observed values of Q = +0.017 +/- 0.013, U = -2.404 +/- 0.110 and Q = +0.021 +/- 0.012, U = -2.353 +/- 0.014, respectively, i.e., a 10-sigma drop in the Q parameter. Our photometric observations gave V = 3.75 +/- 0.01 on Dec.
    [Show full text]
  • Apparent and Absolute Magnitudes of Stars: a Simple Formula
    Available online at www.worldscientificnews.com WSN 96 (2018) 120-133 EISSN 2392-2192 Apparent and Absolute Magnitudes of Stars: A Simple Formula Dulli Chandra Agrawal Department of Farm Engineering, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi - 221005, India E-mail address: [email protected] ABSTRACT An empirical formula for estimating the apparent and absolute magnitudes of stars in terms of the parameters radius, distance and temperature is proposed for the first time for the benefit of the students. This reproduces successfully not only the magnitudes of solo stars having spherical shape and uniform photosphere temperature but the corresponding Hertzsprung-Russell plot demonstrates the main sequence, giants, super-giants and white dwarf classification also. Keywords: Stars, apparent magnitude, absolute magnitude, empirical formula, Hertzsprung-Russell diagram 1. INTRODUCTION The visible brightness of a star is expressed in terms of its apparent magnitude [1] as well as absolute magnitude [2]; the absolute magnitude is in fact the apparent magnitude while it is observed from a distance of . The apparent magnitude of a celestial object having flux in the visible band is expressed as [1, 3, 4] ( ) (1) ( Received 14 March 2018; Accepted 31 March 2018; Date of Publication 01 April 2018 ) World Scientific News 96 (2018) 120-133 Here is the reference luminous flux per unit area in the same band such as that of star Vega having apparent magnitude almost zero. Here the flux is the magnitude of starlight the Earth intercepts in a direction normal to the incidence over an area of one square meter. The condition that the Earth intercepts in the direction normal to the incidence is normally fulfilled for stars which are far away from the Earth.
    [Show full text]
  • Virgo the Virgin
    Virgo the Virgin Virgo is one of the constellations of the zodiac, the group tion Virgo itself. There is also the connection here with of 12 constellations that lies on the ecliptic plane defined “The Scales of Justice” and the sign Libra which lies next by the planets orbital orientation around the Sun. Virgo is to Virgo in the Zodiac. The study of astronomy had a one of the original 48 constellations charted by Ptolemy. practical “time keeping” aspect in the cultures of ancient It is the largest constellation of the Zodiac and the sec- history and as the stars of Virgo appeared before sunrise ond - largest constellation after Hydra. Virgo is bordered by late in the northern summer, many cultures linked this the constellations of Bootes, Coma Berenices, Leo, Crater, asterism with crops, harvest and fecundity. Corvus, Hydra, Libra and Serpens Caput. The constella- tion of Virgo is highly populated with galaxies and there Virgo is usually depicted with angel - like wings, with an are several galaxy clusters located within its boundaries, ear of wheat in her left hand, marked by the bright star each of which is home to hundreds or even thousands of Spica, which is Latin for “ear of grain”, and a tall blade of galaxies. The accepted abbreviation when enumerating grass, or a palm frond, in her right hand. Spica will be objects within the constellation is Vir, the genitive form is important for us in navigating Virgo in the modern night Virginis and meteor showers that appear to originate from sky. Spica was most likely the star that helped the Greek Virgo are called Virginids.
    [Show full text]
  • Ghost Imaging of Space Objects
    Ghost Imaging of Space Objects Dmitry V. Strekalov, Baris I. Erkmen, Igor Kulikov, and Nan Yu Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109-8099 USA NIAC Final Report September 2014 Contents I. The proposed research 1 A. Origins and motivation of this research 1 B. Proposed approach in a nutshell 3 C. Proposed approach in the context of modern astronomy 7 D. Perceived benefits and perspectives 12 II. Phase I goals and accomplishments 18 A. Introducing the theoretical model 19 B. A Gaussian absorber 28 C. Unbalanced arms configuration 32 D. Phase I summary 34 III. Phase II goals and accomplishments 37 A. Advanced theoretical analysis 38 B. On observability of a shadow gradient 47 C. Signal-to-noise ratio 49 D. From detection to imaging 59 E. Experimental demonstration 72 F. On observation of phase objects 86 IV. Dissemination and outreach 90 V. Conclusion 92 References 95 1 I. THE PROPOSED RESEARCH The NIAC Ghost Imaging of Space Objects research program has been carried out at the Jet Propulsion Laboratory, Caltech. The program consisted of Phase I (October 2011 to September 2012) and Phase II (October 2012 to September 2014). The research team consisted of Drs. Dmitry Strekalov (PI), Baris Erkmen, Igor Kulikov and Nan Yu. The team members acknowledge stimulating discussions with Drs. Leonidas Moustakas, Andrew Shapiro-Scharlotta, Victor Vilnrotter, Michael Werner and Paul Goldsmith of JPL; Maria Chekhova and Timur Iskhakov of Max Plank Institute for Physics of Light, Erlangen; Paul Nu˜nez of Coll`ege de France & Observatoire de la Cˆote d’Azur; and technical support from Victor White and Pierre Echternach of JPL.
    [Show full text]
  • 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.
    [Show full text]
  • 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.
    [Show full text]
  • Volume 75 Nos 3 & 4 April 2016 News Note
    Volume 75 Nos 3 & 4 April 2016 In this issue: News Note – Galaxy alignment on a cosmic scale News Note – Presentation of EdinburghMedal Port Elizabeth Peoples’ Observatory Updated Biographical Index to MNASSA and JASSA EDITORIAL Mr Case Rijsdijk (Editor, MNASSA ) BOARD Mr Auke Slotegraaf (Editor, Sky Guide Africa South ) Mr Christian Hettlage (Webmaster) Prof M.W. Feast (Member, University of Cape Town) Prof B. Warner (Member, University of Cape Town) MNASSA Mr Case Rijsdijk (Editor, MNASSA ) PRODUCTION Dr Ian Glass (Assistant Editor) Ms Lia Labuschagne (Book Review Editor) Willie Koorts (Consultant) EDITORIAL MNASSA, PO Box 9, Observatory 7935, South Africa ADDRESSES Email: [email protected] Web page: http://mnassa.saao.ac.za MNASSA Download Page: www.mnassa.org.za SUBSCRIPTIONS MNASSA is available for free download on the Internet ADVERTISING Advertisements may be placed in MNASSA at the following rates per insertion: full page R400, half page R200, quarter page R100. Small advertisements R2 per word. Enquiries should be sent to the editor at [email protected] CONTRIBUTIONS MNASSA mainly serves the Southern African astronomical community. Articles may be submitted by members of this community or by those with strong connections. Else they should deal with matters of direct interest to the community . MNASSA is published on the first day of every second month and articles are due one month before the publication date. RECOGNITION Articles from MNASSA appear in the NASA/ADS data system. Cover picture: An image of the deep radio map covering the ELAIS-N1 region, with aligned galaxy jets. The image on the left has white circles around the aligned galaxies; the image on the right is without the circles.
    [Show full text]
  • 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.
    [Show full text]