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Session 3 - Evolution of Galaxies & Clusters of Galaxies.
Display session, Monday, June 09
South Main Hall,
We present UV images of M31 and M32, 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 are 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 986 sources in M31 and 183 sources in M32. We compare the distribution of stars in the CMDs with the expectations from theory.
Program listing for Monday