Name/Affiliation: Eric Gaidos (University of Hawaii at Manoa)
A Map for the World: An All-Sky Catalog of the Nearest, Brightest M Dwarf Stars
The nearest, brightest M dwarf stars are considered the most propitious targets in the search for and study of Earth-size and habitable, Earth-like planets. We have constructed the largest all-sky catalog of nearby bright M dwarfs to date: ~2600 stars with J<9 selected by parallax or proper-motion and confirmed by spectroscopy and visible and infrared colors. Stars were selected from the Lepine SUPERBLINK proper motion catalog after cross-correlating with the 2-MASS, Hipparcos, Tycho-2 catalog and All-Sky Compiled Catalog v. 2.5. Visible-wavelength photometry was obtained by matching sources in the AAVSO Photometry All-Sky Survey (release 7). Moderate resolution spectra of more than 90% of the catalog were obtained at four telescopes on three continents and Hawaii. Our magnitude-limited catalog is dominated by early-subtype (M0-M4) dwarfs. Calculation of gravity-sensitive indices from these spectra show the contamination rate by giant stars to be much less than 1%. We find the effective temperatures of the stars by fitting predictions of the BT-SETTL version of the PHOENIX stellar atmosphere model to our spectra and calibrating the best-fit temperature against observations of well-characterized Boyajian et al. interferometry targets. We use the empirical relations revised by Mann et al. to convert temperatures into stellar radii, luminosities and masses. These parameters can be used both to estimate the mass or radii of planets found by the Doppler or transit methods, respectively, and for accurately determining the occurrence of planets in the sample. For a subset of the catalog observed by an integral field spectrograph we estimate metallicities and screen for binaries. The distribution of [Fe/H] is Gaussian with a mean of -0.03 dex, consistent with previous studies. Finally, we estimate the number of planets that will be discovered in the habitable zones of these stars by future exoplanet surveys.