Astron. Astrophys. 333, 497-504 (1998)

Brown dwarfs in the Pleiades ^*

II. A deep optical and near infrared survey

L. Festin

Astronomical Observatory, Box 515, S-751 20 Uppsala, Sweden (leif@astro.uu.se)

Received 7 July 1997 / Accepted 5 February 1998

Abstract

The brown dwarf population in the Pleiades cluster has been probed in a deep 850 arcmin² RIJK survey. The survey is complete to in 76 % of the area and to in the remaining 24 %. Photometry of 30 previously known members is presented together with 8 new candidates, four of which are below the brown dwarf limit. The faintest one is the lowest mass brown dwarf candidate found hitherto in the Pleiades (, 0.04 ). The derived Pleiades luminosity function is compared to the most recent theoretical mass-luminosity relations and is consistent with a power-law index in the mass function between 0 and 1 to the limit of this survey.

Key words: stars: late-type stars: low-mass, brown dwarfs stars: luminosity function, mass function open clusters and associations: individual: Pleiades

* Based on observations collected at the Nordic Optical Telescope (NOT), La Palma

Send offprint requests to: L. Festin

SIMBAD Objects

Contents

• 1. Introduction
• 2. Observations and reductions
  • 2.1. Reductions and photometric calibrations
  • 2.2. Completeness limits
  • 2.3. Classification of objects
• 3. Extraction of the Pleiades candidates
  • 3.1. Wide field binaries?
• 4. Contamination
  • 4.1. Giants
  • 4.2. M dwarfs
• 5. Results
  • 5.1. Overall appearance
  • 5.2. Individual objects
  • 5.3. The luminosity function and the mass function
• 6. Summary
• Acknowledgements
• References

© European Southern Observatory (ESO) 1998

Online publication: April 20, 1998
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