Sign on

SAO/NASA ADS Astronomy Abstract Service

· Find Similar Abstracts (with default settings below)
· Full Refereed Journal Article (PDF/Postscript)
· Full Refereed Scanned Article (GIF)
· References in the article
· Citations to the Article (127) (Citation History)
· Refereed Citations to the Article
· SIMBAD Objects (35)
· Also-Read Articles (Reads History)
·
· Translate This Page
Title:
Exploring the brown dwarf desert with Hipparcos
Authors:
Halbwachs, J. L.; Arenou, F.; Mayor, M.; Udry, S.; Queloz, D.
Affiliation:
AA(Equipe "Populations stellaires et evolution galactique", Observatoire Astronomique de Strasbourg (UMR 7550), 11 rue de l'Université, 67 000 Strasbourg ), AB(DASGAL, Observatoire de Paris-Meudon, bat 11, 5 place J. Janssen, 92195 Meudon Cedex, France ), AC(Geneva Observatory, 51 chemin des Maillettes, 1290 Sauverny, Switzerland ), AD(Geneva Observatory, 51 chemin des Maillettes, 1290 Sauverny, Switzerland ), AE(Geneva Observatory, 51 chemin des Maillettes, 1290 Sauverny, Switzerland ; and Jet Propulsion Lab., 4800 Oak Grove Drive, Pasadena, CA 91109, USA )
Publication:
Astronomy and Astrophysics, v.355, p.581-594 (2000) (A&A Homepage)
Publication Date:
03/2000
Origin:
A&A
Astronomy Keywords:
ASTROMETRY, STARS: BINARIES: GENERAL, STARS: BINARIES: SPECTROSCOPIC, STARS: FORMATION, STARS: FUNDAMENTAL PARAMETERS, STARS: LOW-MASS, BROWN DWARFS
Bibliographic Code:
2000A&A...355..581H

Abstract

The orbital elements of 11 spectroscopic binaries with brown dwarf candidates (M2 sin i between 0.01 and 0.08 Msun) are combined with the Hipparcos observations in order to derive astrometric orbits. Estimations of the masses of the secondary components are thus calculated. It appears that 5 secondary masses are more than 2 sigmaM2 above the limit of 0.08 Msun, and are therefore not brown dwarfs. 2 other stars are still discarded at the 1 sigmaM2 level, 1 brown dwarf is accepted with a low confidence, and we are finally left with 3 viable candidates which must be studied by other means. A statistical approach is developed, based on the relation between the semi-major axes of the photocentric orbit, a_0, their errors, sigma a_0, and the frequency distribution of the mass ratios, q. It is investigated whether the set of values of a_0 and sigma a_0 obtained for the sample is compatible with different frequency distributions of q. It is concluded that a minimum actually exists for M2 between about 0.01 and 0.1 Msun for companions of solar-type stars. This feature could correspond to the transition between giant planets and stellar companions. Due to the relatively large frequency of single brown dwarfs found recently in open clusters, it is concluded that the distribution of the masses of the secondary components in binary systems does not correspond to the IMF, at least for masses below the hydrogen-ignition limit. Based on photoelectric radial-velocity measurements collected at Haute-Provence observatory and on observations made with the ESA Hipparcos astrometry satellite.

Printing Options

Send high resolution image to Level 2 Postscript Printer
Send low resolution image to Level 2 Postscript Printer
Send low resolution image to Level 1 Postscript Printer
Get high resolution PDF image
Get low resolution PDF
Send 300 dpi image to PCL Printer
Send 150 dpi image to PCL Printer

More Article Retrieval Options

HELP for Article Retrieval
Bibtex entry for this abstract   Preferred format for this abstract (see Preferences)
   

Find Similar Abstracts:

Use: Authors
Title
Keywords (in text query field)
Abstract Text
Return: Query Results Return    items starting with number
Query Form
Database: Astronomy
Physics
arXiv e-prints