Astronomy Astrophysics
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Astronomy Astrophysics
A&A 406, 995–999 (2003) Astronomy DOI: 10.1051/0004-6361:20030647 & c ESO 2003 Astrophysics High resolution spectroscopy over λλ 8500 8750 Å for GAIA? − IV. Extending the cool MK stars sample P. M. Marrese1;2, F. Boschi1, and U. Munari1 1 Padova Astronomical Observatory - INAF, Asiago Station, Via Osservatorio 8, 36012 Asiago (VI), Italy e-mail: [email protected], [email protected] 2 Department of Astronomy, University of Padova, Vicolo Osservatorio 8, 35122 Padova, Italy Received 12 December 2002 / Accepted 24 April 2003 Abstract. A library of high resolution spectra of MK standard and reference stars, observed in support to the GAIA mission, is presented. The aim of this paper is to integrate the MK mapping of Paper I of this series as well as to consider stars over a wider range of metallicities. Radial velocities are measured for all the target stars. Key words. atlases – standards – stars: fundamental parameters 1. Introduction 2 and 3 give examples of the collected spectra and illustrate respectively the effect of gravity and metallicity at G5 (com- This paper is the fourth of a series devoted to the spectroscopy pare with Fig. 2 in Paper I), the effect of gravity at F5 and at of the ESA Cornerstone mission GAIA. The GAIA Radial K4. Velocity Spectrometer (RVS) will provide the 6th component of the phase-space coordinates for all stars brighter than V = 2. Target selection 17:5 magnitude. High resolution (R 20 000) high signal to Table 1 lists the target stars, ordered by spectral type, and noise (S=N 100) spectra of cool (later∼ than F0) MK stan- Table 2 the references to it. -
Confirmation of the Molecular Layer Model
A&A 426, 279–296 (2004) Astronomy DOI: 10.1051/0004-6361:20041098 & c ESO 2004 Astrophysics Unveiling Mira stars behind the molecules, Confirmation of the molecular layer model with narrow band near-infrared interferometry G. Perrin1,S.T.Ridgway1,2, B. Mennesson3,W.D.Cotton4, J. Woillez1,5, T. Verhoelst1,6, P. Schuller7, V. Coud´e du Foresto1,W.A.Traub7, R. Millan-Gabet8, and M. G. Lacasse7 1 Observatoire de Paris, LESIA, UMR 8109, 92190 Meudon, France e-mail: [email protected] 2 National Optical Astronomy Observatories, Tucson, AZ 85726-6732, USA 3 Jet Propulsion Laboratory, California Institute of Technology, MS 306-388, 4800 Oak Grove Drive, Pasadena, CA 91109, USA 4 National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475, USA 5 Keck Observatory, 65-1120 Mamalahoa Highway, Kamuela, HI 96743, USA 6 Sterrenkunde Leuven, Leuven, Belgium 7 Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA 8 Caltech/Michelson Science Center, Pasadena, CA 91125, USA Received 15 April 2004 / Accepted 15 June 2004 Abstract. We have observed Mira stars with the FLUOR beamcombiner on the IOTA interferometer in narrow bands around 2.2 µm wavelength. We find systematically larger diameters in bands contaminated by water vapor and CO. The visi- bility measurements can be interpreted with a model comprising a photosphere surrounded by a thin spherical molecular layer. The high quality of the fits we obtain demonstrates that this simple model accounts for most of the star’s spatial structure. For each star and each period we were able to derive the radius and temperature of the star and of the molecular layer as well as the optical depth of the layer in absorption and continuum bands. -
Direct Detection of a Magnetic Field in The
A&A 524, A57 (2010) Astronomy DOI: 10.1051/0004-6361/201014503 & c ESO 2010 Astrophysics Direct detection of a magnetic field in the photosphere of the single M giant EK Bootis How common is magnetic activity among M giants? R. Konstantinova-Antova1 ,2, M. Aurière2, C. Charbonnel3,2,N.A.Drake4, K.-P. Schröder5, I. Stateva1, E. Alecian6, P. Petit2, and R. Cabanac2 1 Institute of Astronomy, Bulgarian Academy of Sciences, 72 Tsarigradsko shose, 1784 Sofia, Bulgaria e-mail: [email protected] 2 Laboratoire d’Astrophysique de Toulouse-Tarbes, Université de Toulouse, CNRS, Observatoire Midi Pyrénés, 57 Avenue d’Azereix, 65008 Tarbes, France 3 Observatoire Astronomique de l’Université de Genève, 51 Chemin des Maillettes, 1290 Versoix, Switzerland 4 Sobolev Astronomical Institute, St. Petersburg State University, Universitetski pr. 28, St. Petersburg 198504, Russia 5 Departamento de Astronomia, Universidad de Guanajuato, A.P. 144, C.P. 36000, GTO, Mexico 6 Laboratoire d’Astrophysique de Grenoble, Université Joseph Fourier-CNRS, BP 53, 38041 Grenoble Cedex 9, France Received 25 March 2010 / Accepted 1 September 2010 ABSTRACT Aims. We study the fast rotating M 5 giant EK Boo by means of spectropolarimetry to obtain direct and simultaneous measurements of both the magnetic field and activity indicators, in order to infer the origin of the activity in this fairly evolved giant. Methods. We used the new spectropolarimeter NARVAL at the Bernard Lyot Telescope (Observatoire du Pic du Midi, France) to obtain a series of Stokes I and Stokes V profiles for EK Boo. Using the least square deconvolution (LSD) technique we were able to detect the Zeeman signature of the magnetic field. -
The M Giants EK Bootis and Β Pegasi
Magnetism in Cool Evolved Stars: the M giants EK Bootis and β Pegasi S. Georgiev1,2, R. Konstantinova-Antova1, A. L`ebre2, M. Auri`ere3, C. Charbonnel3,4, A. Palacios2, N. Drake5,6,7, R. Bogdanovski1 1 Institute of Astronomy and NAO, Bulgarian Academy of Science, 1784 Sofia, Bulgaria 2 LUPM, UMR 5299, Universit´ede Montpellier, CNRS, place Eug`ene Bataillon, 34095 Montpellier, France 3 Universit´ede Toulouse, Institut de Recherche en Astrophysique et Plan´etologie, 14 avenue Edouard´ Belin, 31400 Toulouse, France 4 Department of Astronomy, University of Geneva, Chemin des Maillettes 51, 1290 Versoix, Switzerland 5 Laboratory of Observational Astrophysics, Saint Petersburg State University, Universitetski pr. 28, Petrodvoretz 198504, Saint Petersburg, Russia 6 Observat´orio Nacional/MCTIC, Rua Gen. Jos´eCristino, 77, 20921-400, Rio de Janeiro, Brazil 7 Laborat´orio Nacional de Astrof´ısica/MCTIC, Rua dos Estados Unidos 154, 37504-364, Itajub´a, Brazil [email protected] (Submitted on 04.11.2019. Accepted on 18.02.2020) Abstract. We present a long-term spectropolarimetric study of the active M giants EK Bootis (M5III) and β Pegasi (M2.5II-III). For each star, the variability of the disk- averaged longitudinal component of the magnetic field (Bl) is shown, along with the behavior of different spectral activity indicators. The possible nature of the secondary component of EK Boo is discussed. We compare the observed variations in the activ- ity proxies of each of the two giants and discuss possible physical explanations for the structure of their respective magnetic fields. For both objects, observations in linear po- larisation are also presented and briefly discussed. -
Carnegie Institution of Washington
CARNEGIE INSTITUTION OF WASHINGTON MOUNT WILSON OBSERVATORY PASADENA, CALIFORNIA LIST OF LANTERN SLIDES AND PHOTOGRAPHS 1932 PRICES ADD S PER CENT FOR POSTAGE AND PACKING SLIDES 4x 3 ~ IN., 75 CENTS EACH CERTAIN SLIDES HAY BE COLORED TO ORDER AT AN ADDITIONAL CHARGE OF 75 CENTS EACH PAPER PRINTS 8x10 IN., 50 CENTS EACH 16x20 IN. FROM ALL M!•RKED•, $2.01) EACH OTHER ENLARGEMENTS WILL Bl! MADE TO ORDER TRANSPARENCIES GLASS 8xl0 IN., $2.00 10x12 IN., 3.00 14x17 IN., 6.00 16x20 IN., 8.00 TRANSPARENCIES MOUNTED WITH GROUND-CLASS 20 PER CENT EXTRA FILM SxlO IN., $1.50 10x12 IN., 2.50 14x17 IN., 4.00 16x20 IN., 5.00 LIST OF SLIDES AND PHOTOGRAPHS SERIES A. INSTRUMENTS AND BUILDINGS A 2 Snow telescope building from the southeast Snow coelostat and second mirror from the southeast 4 Snow coelostat and second mirror from inside the rolling shelter 5 Interior of the Snow telescope showing concave mirror 6 Five-foot spectroheliograph showing the slit end 7 Five-foot spectroheliograph showing the optical train 10 Sixty-foot tower telescope from the northeast 16 Interior of the physical laboratory in Pasadena 17 Diagram of the one-hundred-fifty-foot tower telescope 18 Diagram of the upper end of the one-hundred-fifty-foot tower telescope and dome 20 Sixty-foot dome from the east 21 Sixty-foot dome from the sixty-foot tower 22 Sixty-inch reflecting telescope from the west 25 Sixty-inch reflecting telescope show ing plate-holder attachment 26 Sixty-inch mirror on grinding machine tipped forward for testing 27 Sixty-inch reflecting telescope with Cassegrain spectrograph •28 Dome of the one-hundred-inch Hooker reflector from the south showing shutter open 29 One-hundred-fifty-foot tower telescope from the sixty-foot tower tele- scope •30 One-hundred-fifty-foot tower telescope from the northeast 31 Top of the seventy-five-foot spectrograph 32 One-hundred-foot dome from the one-hundred-fifty-foot tower 33 Model of top of Mt. -
Interferometric Observations of the Supergiant Stars Α Orionis and Α Herculis with FLUOR at IOTA
A&A 418, 675–685 (2004) Astronomy DOI: 10.1051/0004-6361:20040052 & c ESO 2004 Astrophysics Interferometric observations of the supergiant stars α Orionis and α Herculis with FLUOR at IOTA G. Perrin1,S.T.Ridgway2, V. Coud´e du Foresto1, B. Mennesson3,W.A.Traub4, and M. G. Lacasse4 1 Observatoire de Paris, LESIA, UMR 8109, 92190 Meudon, France 2 National Optical Astronomy Observatories, Tucson, AZ 85726-6732, USA 3 Jet Propulsion Laboratory, California Insititute of Technology, MS 306-388, 4800 Oak Grove Drive, Pasadena, CA 91109, USA 4 Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA Received 3 February 2003 / Accepted 30 January 2004 Abstract. We report the observations in the K band of the red supergiant star α Orionis and of the bright giant star α Herculis with the FLUOR beamcombiner at the IOTA interferometer. The high quality of the data allows us to estimate limb-darkening and derive precise diameters in the K band which combined with bolometric fluxes yield effective temperatures. In the case of Betelgeuse, data collected at high spatial frequency although sparse are compatible with circular symmetry and there is no clear evidence for departure from circular symmetry. We have combined the K band data with interferometric measurements in the L band and at 11.15 µm. The full set of data can be explained if a 2055 K layer with optical depths τK = 0.060 ± 0.003, τL = 0.026 ± 0.002 and τ11.15 µm = 2.33 ± 0.23 is added 0.33 R above the photosphere providing a first consistent view of the star in this range of wavelengths. -
Spectroscopic Binaries Among Hipparcos M Giants I. Data, Orbits
Astronomy & Astrophysics manuscript no. binairesM˙orbites.20081213 c ESO 2018 October 23, 2018 Spectroscopic binaries among Hipparcos M giants⋆,⋆⋆ I. Data, orbits, and intrinsic variations B. Famaey⋆⋆⋆,1, D. Pourbaix†,1, A. Frankowski‡,1, S. Van Eck†,1, M. Mayor2, S. Udry2, and A. Jorissen1 1 Institut d’Astronomie et d’Astrophysique, Universit´elibre de Bruxelles, Facult´edes Sciences, CP. 226, Boulevard du Triomphe, B-1050 Bruxelles, Belgium 2 Observatoire de Gen`eve, Universit´ede Gen`eve, CH-1290 Sauverny, Switzerland Received date; accepted date ABSTRACT Context. This paper is a follow-up on the vast effort to collect radial velocity data for stars belonging to the Hipparcos survey. Aims. We aim at extending the orbital data available for binaries with M giant primaries. The data presented in this paper will be used in the companion papers of this series to (i) derive the binary frequency among M giants and compare it to that of K giants (Paper II) and (ii) analyse the eccentricity – period diagram and the mass-function distribution (Paper III). Methods. Keplerian solutions are fitted to radial-velocity data. However, for several stars, no satisfactory solution could be found, even though the radial-velocity standard deviation is greater than the instrumental error, because M giants suffer from intrinsic radial- velocity variations due to pulsations. We show that these intrinsic radial-velocity variations can be linked with both the average spectral-line width and the photometric variability. Results. We present an extensive collection of spectroscopic orbits for M giants with 12 new orbits, plus 17 from the literature. -
1. Introduction
THE ASTRONOMICAL JOURNAL, 116:981È986, 1998 August ( 1998. The American Astronomical Society. All Rights Reserved. Printed in U.S.A. RADII AND EFFECTIVE TEMPERATURES FOR K AND M GIANTS AND SUPERGIANTS. II. H. M. DYCK Department of Astrometry, US Naval Observatory, Navy Prototype Optical Interferometer, Rural Route 14, Box 447, Flagsta†, AZ 86001; meldyck=sextans.lowell.edu G. T. VAN BELLE1 Jet Propulsion Laboratory, Mail Stop 306-388, 4800 Oak Grove Drive, Pasadena, CA 91109; gerard=huey.jpl.nasa.gov AND R. R. THOMPSON1 Department of Physics and Astronomy, University of Wyoming, Laramie, WY 82071; thompson=sparky.uwyo.edu Received 1998 February 10; revised 1998 April 7 ABSTRACT We present new interferometric observations for 74 luminous red stars, made in the near-infrared. We show that our 2.2 km uniform-disk diameters agree with other near-infrared diameter determinations (lunar occultations and interferometers) for 22 stars measured in common with ours. From our new data, we derive e†ective temperatures that are compared with our previous work and with comparable obser- vations made by lunar occultations at Kitt Peak. The combined data set yields 91 luminosity class II, IIÈIII, and III stars that have well-determined spectral types spanning the range from about K0 to about M8. There are 83 stars in the sample that deÐne an approximately linear relationship between spectral type and e†ective temperature for giants, with a dispersion of 192 K at each spectral type. Eight of the stars have temperatures that are roughly 750 K too low for their spectral types. These stars are not known to be at the high-luminosity end of the range of stars observed and are not recognized as binary stars.