Metallicities of M dwarfs: J and K bands

Above solar metallicity, the number of stars with planets and presence of multiple planets increases for solar-type stars [1, 2]. Metallicity determination of M dwarf planet hosts are controversial since they have shown abundances below solar metallicity when measured with optical spectra and photometry, suggesting that M dwarfs have a planetary formation process that differs from F, G and K dwarfs. This unexpected result can be due to statistics, with only 7 M dwarfs with planetary candidates known until date, or it can be attributed to the lack of reliable abundances estimates for this type of stars. We are currently attempting to estimate metal abundances of these stars using near infrared spectra of M dwarfs with a wide solar type star companion of known metallicity. Preliminary results from the spectra of 14 M dwarfs using the TripleSpec spectrograph operating on the Palomar 200-inch Hale Telescope are shown here.