Search for and Study of the Brightest Stars in the Galaxy IC 342

Abstract

We have selected candidate massive stars in the galaxy IC 342 based on archival images from the Hubble Space Telescope and images from the 2-m telescope at the National Astronomical Observatory, Rozhen, Bulgaria. Spectral observations of 24 out of 27 selected stars are carried out with the 6-m BTA telescope of SAO RAS and with the 3.5-m Apache Point Observatory telescope (USA) as part of the program for searching for bright massive stars in galaxies outside the Local Group. Our analysis reveals that 12 objects have spectra lacking prominent features, except for the emission lines of the surrounding nebulae and are identified as single supergiants of classes O9 to F5 or spatially unresolved young compact clusters. One source with an absorption spectrum probably belongs to our Galaxy. The spectra of seven other objects show features typical of Wolf–Rayet stars or compact clusters containing Wolf–Rayet stars. Another source is a compact supernova remnant. Two other objects are tentatively classified as cold LBV candidates, and one object is classified as a B[e]-supergiant candidate.