A planet-sized transiting star around OGLE-TR-122 - Accurate mass and radius near the Hydrogen-burning limit
Abstract
We report the discovery and characterisation of OGLE-TR-122b, the smallest main-sequence star to date with a direct radius determination. OGLE-TR-122b transits around its solar-type primary every 7.3-days. With M=0.092+-0.009 Mo and R=0.120 +0.024-0.013 Ro, it is by far the smallest known eclipsing M-dwarf. The derived mass and radius for OGLE-TR-122b are in agreement with the theoretical expectations. OGLE-TR-122b is the first observational evidence that stars can indeed have radii comparable or even smaller than giant planets. In such cases, the photometric signal is exactly that of a transiting planet and the true nature of the companion can only be determined with high-resolution spectroscopy.
Cite
@article{arxiv.astro-ph/0501611,
title = {A planet-sized transiting star around OGLE-TR-122 - Accurate mass and radius near the Hydrogen-burning limit},
author = {F. Pont and C. H. F. Melo and F. Bouchy and S. Udry and D. Queloz and M. Mayor and N. C. Santos},
journal= {arXiv preprint arXiv:astro-ph/0501611},
year = {2009}
}
Comments
4 pages, 3 figures, A&A letters, in Press. Revised