Paper: astro-ph/0511278
Date: Wed, 9 Nov 2005 18:09:45 GMT (23kb)

Title: Proper motion Pleiades candidate L-type brown dwarfs

Authors: G. Bihain, R. Rebolo, V. J. S. Bejar, J. A. Caballero, C. A. L.
Bailer-Jones, R. Mundt

Comments: 2 pages, 2 figures, ULMSF Workshop, accepted for publication in
Astron. Nachrichten
\\
We present results of an optical and near-infrared (IR) 1.8 deg^2 survey in
the Pleiades open cluster to search for substellar objects. From optical I-band
images from the CFHT and J-band images from the 3.5 m CAHA Telescope, we
identify 18 faint and very red L brown dwarf candidates, with I> 20.9 and I-J>
3.2. The follow-up observations of nine objects in the H- and Ks-bands confirm
that eight belong to the IR sequence of the cluster and the proper motion
measurements of seven candidates confirm that they are Pleiades members. A
preliminary estimation of the substellar mass spectrum dN/dM in the form of a
power law M^-alpha provides alpha=0.57+-0.14. We extrapolate this function to
estimate the number of very low-mass brown dwarfs and planetary mass objects
that could be present in the cluster down to 1 M_Jup. Sensitive searches
combining far red and near infrared observations may unveal these objects in a
near future.

\\ ( http://arXiv.org/abs/astro-ph/0511278 , 23kb)