THE GALACTIC DISTRIBUTION OF WOLF-RAYET STARS

Abstract

The results of the investigation of the Galaxy distribution of Wolf-Rayet stars have been presented. This investigation is important for the understanding of the evolutionary properties WR stars. It is known that in the formation of these stars, the main factor is the mass loss rate. Massive O star by losing a significant amount of mass transforms into WR star. On the other hand, the mass loss rate depends on metallicity. It is known that metallicity in our Galaxy decreases from the center to the outer parts. Therefore, by investigating the galaxy distribution of WR stars we could clarify the role of metallicity in the formation of these stars. WR stars separate into WN, WC, and WO subtypes. We could also clarify the evolutionary relations between different subtypes. By using the correct values of distances we plotted the galactic distribution of WR stars. Although the Galactic distribution of these stars has also been carried out before, it is important to perform new research. Because every year new stars are discovered and the distances to these stars are already determined correctly than used in earlier researches.