Proper motion of very low mass stars and brown dwarfs in the Pleiades cluster*
Laboratoire d'Astrophysique, Observatoire de Grenoble, Université Joseph Fourier, BP 53, 38041 Grenoble Cedex 9, France
2 SIRTF Science Center, Caltech, Pasadena, CA 91125, USA
Corresponding author: E. Moraux, email@example.com
Accepted: 30 November 2000
We report proper motion measurements for 25 very-low mass (VLM) star and brown dwarf (BD) candidates of the Ple iades cluster previously identified by Bouvier et al. ([CITE]). Proper motions are measured with an accuracy of 9 mas/yr, compared to an expected tangential motion of about 50 mas/yr for Pleiades members. Of the 25 candidates, 15 have a membership probability of 95% or more and 7 are rejected as being field dwarfs. The 3 remaining candidates exhibit independent evidence for membership (lithium absorption or long-term proper motion). From the firm identification of Pleiades VLM and BD members, the cluster's substellar mass function is revised to in the mass range from 0.04 to 0.3 .
Key words: stars: low-mass, brown dwarfs / stars: luminosity function, mass function / Galaxy: open clusters and associations: individual: Pleiades
© ESO, 2001