Metallicities of M dwarfs: J and K bands

摘要

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