A catalog of known Galactic K-M stars of class I, candidate RSGs, in
  Gaia DR2
  We investigate individual distances and luminosities of a sample of 889
nearby candidate red supergiants with reliable parallaxes (plx/plxerr > 4 and
RUWE < 2.7) from Gaia DR2. The sample was extracted from the historical
compilation of spectroscopically derived spectral types by Skiff (2014), and
consists of K-M stars that are listed with class I at least once. The sample
includes well-known red supergiants from Humphreys (1978), Elias et al. (1985),
Jura and Kleinmann (1990), and Levesque et al. (2005). Infrared and optical
measurements from the 2MASS, CIO, MSX, WISE, MIPSGAL, GLIMPSE, and NOMAD
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 red supergiants with Mbol<-7.1 mag. 43% of the
sample is made of stars with masses > 7 Msun. Another 30% of the sample
consists of giant stars.
