Testing the Planet-Metallicity Correlation in M-dwarfs with Gemini GNIRS Spectra
Published in Revista Mexicana de Astronomía y Astrofísica, 2017
Recommended citation: Hobson, M.J. et al. (2018). "The SOPHIE search for northern extrasolar planets XIII. Two planets around M-dwarfs Gl617A and Gl96" Revista Mexicana de Astronomía y Astrofísica. 54, 65. https://www.astroscu.unam.mx/rmaa/RMxAA..54-1/PDF/RMxAA..54-1_mhobson-V.pdf
While the planet-metallicity correlation for FGK main-sequence stars hosting giant planets is well established, it is less clear for M-dwarf stars. We determine stellar parameters and metallicities for 16 M-dwarf stars, 11 of which host planets, with near-infrared spectra from the Gemini Near-Infrared Spectrograph (GNIRS). We find that M-dwarfs with planets are preferentially metal-rich compared to those without planets. This result is supported by the analysis of a larger catalogue of 18 M stars with planets and 213 M stars without known planets T15, and demonstrates the utility of GNIRS spectra to obtain reliable stellar parameters of M stars. We also find that M dwarfs with giant planets are preferentially more metallic than those with low-mass planets, in agreement with previous results for solar-type stars. These results favor the core accretion model of planetary formation.