A Catalog of Known Galactic K-M Stars of Class I Candidate Red Supergiants in Gaia DR2

We investigate individual distances and luminosities of a sample of 889 nearby candidate red supergiants (RSGs) with reliable parallaxes (ϖ/σ _ϖ > 4 and RUWE < 2.7) from Gaia Data Release 2 (DR2). The sample was extracted from the historical compilation of spectroscopically derived spectral types by Skiff, and consists of K-M stars that are listed with class I at least once. The sample includes well-known RSGs from Humphreys, Elias et al., Jura & Kleinmann, and Levesque et al. Infrared and optical measurements from the Two Micron All Sky Survey, Catalog of Infrared Observations (CIO), Midcourse Space Experiment, Wide-field Infrared Survey Explorer, MIPSGAL, Galactic Legacy Infrared Midplane Extraordinaire (GLIMPSE), and The Naval Observatory Merged Astrometric Dataset catalogs allow us to estimate the stellar bolometric magnitudes. We analyze the stars in the luminosity versus effective temperature plane and confirm that 43 sources are highly probably RSGs with {M}_bol} < -7.1 mag. Of the stars in the sample, 43% have masses >7 M _⊙. Another ≈30% of the sample consists of giant stars.