A Methane Isolated Planetary Mass Object in Orion
Abstract
We report on the discovery of a free-floating methane dwarf toward the direction of the young star cluster sigma Orionis. Based on the object's far-red optical and near-infrared photometry and spectroscopy, we conclude that it is a possible member of this association. We have named it as S Ori J053810.1-023626 (S Ori 70 is the abridged name). If it is a true member of sigma Orionis, the comparison of the photometric and spectroscopic properties of S Ori 70 with state-of-the-art evolutionary models yields a mass of 3 (+5/-1) Jupiter mass for ages between 1 Myr and 8 Myr. The presence of such a low-mass object in our small search area (55.4 sq. arcmin) would indicate a rising substellar initial mass function in the sigma Orionis cluster even for planetary masses.
Keywords
Cite
@article{arxiv.astro-ph/0206353,
title = {A Methane Isolated Planetary Mass Object in Orion},
author = {M. R. Zapatero Osorio and V. J. S. Bejar and E. L. Martin and R. Rebolo and D. Barrado y Navascues and R. Mundt and J. Eisloeffel and J. A. Caballero},
journal= {arXiv preprint arXiv:astro-ph/0206353},
year = {2009}
}
Comments
Accepted for publication in the ApJ. Twelve pages, figures and tables included