Program: GN-2012B-Q-23

Precise metallicity measurements of large samples of FGK-dwarfs planet host stars have revealed that the gas giant planet frequency rises with host star metallicity, relation known as the planet-metallicity correlation. In constrast, recent measurements, using photometric calibrations, suggest that M dwarfs harboring planets are metal rich regardless of the mass of the planet (Schlaufman & Laughlin 2010). We propose to observe a sample of 3 M dwarfs with planets and 4 stars without detected planets, with the GNIRS spectrograph in the cross-dispersed mode (1.2-2.5 mu) at R~5000, to derive precise metallicities using recent near infrared spectroscopic calibrations (Rojas-Ayala et al. 2010, Terrien et al. 2012). Confirmation of the results found by Schlaufman & Laughlin will help to set better constraints on planet formation models. In addition, these observations will allow us to review the infrared calibrations in an independent manner and make a comparative study with the photometric metallicity scales.