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Description
Using the Position and Proper Motion Extended-L (PPMXL) catalog, the authors have used optical and near-infrared color cuts together with a reduced proper motion cut to find bright M dwarfs for future exoplanet transit studies. PPMXL's low proper-motion uncertainties allow them to probe down to smaller proper motions than previous similar studies. The authors have combined unique objects found with this method to that of previous work to produce 8,479 K < 9th magnitude M dwarfs. Low-resolution spectroscopy was obtained of a sample of the objects found using this selection method to gain statistics on their spectral type and physical properties. Results show a spectral-type range of K7 to M4V. This catalog is the most complete collection of K < 9 M dwarfs currently available and is made available herein. The PPMXL catalog (Roeser et al. 2010) represents a combination of the USNO-B1.0 and Two Micron All-Sky Survey (2MASS) catalogs mapped on to the International Celestial Reference Frame (ICRF), which allows proper motions to be described in a quasi-absolute manner as opposed to relative. PPMXL now provides low uncertainties for both the proper motion and position for many of the objects within the two catalogs. Typical uncertainties for proper motions are 4 - 10 mas/yr. The NIR JHK magnitudes from 2MASS and the optical BVRI magnitudes from USNO-B1.0 also provide very useful color information about the objects and are used during the sample selection process. In this work, the authors classified 4,054 M dwarfs with magnitudes of K < 9 from the PPMXL catalog. By probing down to lower proper motions, this work has produced 1,193 new bright M dwarf candidates that were not included in previous catalogs. By combining these objects with M dwarfs from Lepine & Gaidos (2011, AJ, 142, 138) the authors obtained a final catalog with 8,479 K < 9 late K and M dwarfs suitable for future exoplanet transit studies. This table was created by the HEASARC in February 2015 based on the <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/MNRAS/435/2161">CDS Catalog J/MNRAS/435/2161</a> file table3.dat. This is a service provided by NASA HEASARC .
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