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Hot Evolved Stars in the Centers of M 31 and M 32

T. M. Brown·H. C. Ferguson·S. A. Stanford·J. -M. Deharveng·A. F. Davidsen
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Abstract

We present UV images of M 31 and M 32, as observed by HST with the refurbished FOC. The galaxies were observed through the F175W and F275W filters, allowing the construction of color magnitude diagrams (CMDs) for the hundreds of detected sources found in each image. Comparison of these data with the stellar evolutionary tracks of horizontal branch stars and their progeny shows that for the first time outside of our own Galaxy, we may be measuring the colors of individual stars that are evolving along post asymptotic giant branch (PAGB), post-early AGB, and AGB-Manque' paths. Searching to the 6 sigma detection limit, we find 1349 stars in M 31 and 183 stars in M 32. We compare the distribution of stars in the CMDs with the expectations from theory.

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T. M. Brown, H. C. Ferguson, S. A. Stanford, J. -M. Deharveng, A. F. Davidsen. 1997-06-19. Hot Evolved Stars in the Centers of M 31 and M 32. https://doi.org/10.1063/1.53746

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