Astron. Astrophys. 339, 405-408 (1998)

The contribution of brown dwarfs to the local mass budget of the Galaxy

B. Fuchs ¹, H. Jahreiß ¹ and C. Flynn <sup>2

1</sup> Astronomisches Rechen-Institut Heidelberg, Mönchhofstrasse 12-14, D-69120 Heidelberg, Germany
² Tuorla Observatory, Väisäläntie 20, Piikkiö, Finland

Received 2 June 1998 / Accepted 12 August 1998

Abstract

Based on the recent discoveries of free floating brown dwarfs we derive estimates of the local mass density of this population of objects. Mass density estimates from various surveys span the range 0.03 to 0.005 pc^-3. These estimates are compared with the local mass densities of the other constituents of the galactic disk and, in particular, with the dynamically determined total local mass density. We argue that brown dwarfs might indeed contribute significantly to the local mass budget, but that a local mass density as high as 0.03 pc^-3 as suggested by Ruiz et al. (1997) is rather unlikely.

Key words: stars: low-mass, brown dwarfs stars: kinematics stars: statistics

Send offprint requests to: B. Fuchs (fuchs@ari.uni-heidelberg.de)

SIMBAD Objects

Contents

• 1. Introduction
• 2. Estimates of the local mass density of brown dwarfs
  • 2.1. Calan-ESO proper motion survey
  • 2.2. DENIS mini survey
  • 2.3. BRI survey
  • 2.4. UK Schmidt survey
• 3. Discussion and conclusions
• Acknowledgements
• References

© European Southern Observatory (ESO) 1998

Online publication: October 21, 1998
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