Characterization of extrasolar planetary transiting candidates II

TL;DR

This paper characterizes stars with low-depth transits from OGLE-III to identify promising exoplanet candidates, especially around M and K type stars, and discusses potential discoveries of planets orbiting late M dwarfs.

Contribution

It provides detailed physical parameters for transit candidates and identifies the most promising M-type stars for hosting exoplanets, including potential planets around late M dwarfs.

Findings

Eight M and K type stars identified as potential hosts.

Four stars are the most promising M-type transit candidates.

Potential discovery of planets orbiting late M dwarfs around 2900 K.

Abstract

We present a second paper of fully characterization of a sample of stars whose low-depth transits were discovered by the OGLE-III campaign in order to select the most promising candidates for spectroscopic confirmation, following the same analysis done in Gallardo et al. (2005). We present new optical and near-IR photometry, deriving physical parameters like effective temperature (Teff), distance (d), the stellar radii (R*) and the companion radii (Rc). We selected eight M (2800 K \le Teff \le 3850 K) or K (3850 K \le Teff \le 5150 K) spectral type stellar objects as potential candidates to host exoplanets, even though, considering the radii of their companions, only stars OGLE-TR-61, OGLE-TR-74, OGLE-TR-123 and OGLE-TR-173 are the most promising M-type transit candidates to host planets. Confirmation of the planetary nature of any of these objects will yield another transiting extrasolar planet orbiting a M-type star, or even more interesting, the first extrasolar planets orbiting a late M-type dwarf of effective temperature about 2900 K.