Proper motion Pleiades candidate L-type brown dwarfs
Abstract
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.
Cite
@article{arxiv.astro-ph/0511278,
title = {Proper motion Pleiades candidate L-type brown dwarfs},
author = {G. Bihain and R. Rebolo and V. J. S. Bejar and J. A. Caballero and C. A. L. Bailer-Jones and R. Mundt},
journal= {arXiv preprint arXiv:astro-ph/0511278},
year = {2009}
}
Comments
2 pages, 2 figures, ULMSF Workshop, accepted for publication in Astron. Nachrichten