a test Assigned ID: 727 ----- Attempting Submission 1 (Fri Feb 25 22:39:13 GMT 2011) ----- HST Phase I Proposal 727 (MGC_SC_19AR.v23.pdf.apt) successfully submitted. ----- Attempting Submission 2 (Fri Feb 25 22:46:46 GMT 2011) ----- HST Phase I Proposal 727 (MGC_SC_19AR.v23.pdf.apt) successfully submitted. ----- Attempting Submission 3 (Fri Feb 25 23:07:11 GMT 2011) ----- HST Phase I Proposal 727 (MGC_SC_19AR.v23.pdf.apt) successfully submitted. ----- Attempting Submission 4 (Tue Mar 01 16:18:00 GMT 2011) ----- The discovery of widespread abundance variations in Milky Way Globular Clusters brought renewed interest in their star formation histories. Simulations suggest that the star formation timescale in a globular cluster must be on the order of 100 Myr in most cases and not longer than 500 Myr. This age spread is too small to be detectable in CMDs of ancient globular clusters in the Milky Way, even with HST/ACS. However, many populous, intermediate-age star clusters in the Magellanic Clouds were recently found to possess broadened main sequence turnoffs. This renders these clusters very powerful probes of the history of star formation in star clusters. We propose to derive CMDs from high-precision ePSF fitting photometry, corrected for instrumental imperfections, for 21 Magellanic Cloud star clusters. These CMDs constitute a unique, homogeneous, and statistically significant sample to 1) study cluster formation via the shape of the age distribution and chemical abundance variation; 2) improve our understanding of stellar astrophysics, particularly convective core overshoot and rotation which have important implications for the turnoff stars in these clusters; 3) provide an accurate library of the properties star clusters which will serve as a reference for studies of both resolved and unresolved studies of intermediate age stellar populations. We plan to make the photometry catalogs and stellar models produced for this project publicly available, ensuring our efforts will have a lasting value.

RESOLVED STELLAR POPULATIONS 12 Medium false 0.0 0.0 false false false false SUPPORTED