Physical properties of red supergiants

We aim to increase the sample of well-characterized RSGs at subsolar metallicity, by deriving the physical properties of 127 RSGs in nine nearby, southern galaxies presented by Bonanos et al. For each RSG, we provide spectral types and used MARCS atmospheric models to measure stellar properties from their optical spectra, such as the effective temperature, extinction, and radial velocity.

By fitting the spectral energy distribution, we obtained the stellar luminosity and radius for 92 RSGs, finding ~50% with log(L/L_{sun}_)>5.0 and 6 RSGs with R>1400R_{sun}_. We also find a correlation between the stellar luminosity and mid-IR excess of 33 dusty, variable sources. Three of these dusty RSGs have luminosities exceeding the revised Humphreys-Davidson limit.