The role of episodic mass loss in massive star evolution is one of the outstanding questions of current stellar evolution theory. Episodic mass loss produces dust and therefore causes evolved massive stars to be very luminous in the mid-infrared and dim at optical wavelengths. We aim to increase the number of investigated luminous mid-IR sources to shed light on the late stages of these objects. To achieve this we explore mid-IR selection criteria to identity dusty evolved massive stars in two nearby galaxies. The method is based on mid-IR colors, using 3.6um and 4.5um photometry from archival Spitzer Space Telescope images of nearby galaxies and J-band from 2MASS. We apply our criteria to two nearby star-forming dwarf-irregular galaxies: Sextans A and IC 1613, selecting 8 targets, which we follow up with spectroscopy. Our spectral classification and analysis yielded the discovery of 2 M-type supergiants in IC 1613, 3 K-type supergiants and 1 candidate F-type giant in Sextans A, and 2 foreground M giants. We show that the proposed criteria provide an independent way for identifying dusty evolved massive stars, which can be extended to all nearby galaxies with available Spitzer/IRAC images at 3.6um and 4.5um.

Cone search capability for table J/A+A/562/A75/stars (Characteristics of the program stars, log of observations, radial velocities, CaT* indices and spectral types)