fixed typos Assigned ID: 1002 ----- Attempting Submission 1 (Sat Feb 26 19:24:13 GMT 2011) ----- HST Phase I Proposal 1002 (wCen.apt) successfully submitted. ----- Attempting Submission 2 (Sat Feb 26 20:42:17 GMT 2011) ----- We propose to construct the most comprehensive catalog of photometry and proper motions ever assembled for a globular cluster (GC). The core of Omega Centauri has been imaged nearly 500 times through WFC3's UVIS and IR channels for the purposes of detector calibration. There exist ~30 exposures through each of 15 filters, stretching uniformly from F225W in the UV to F160W in the infrared. Furthermore, the 8-year baseline between this data and a 2002 ACS survey will more than double the accuracy and triple the number of well-measured stars compared to our previous groundbreaking effort. This totally unprecedented complete spectral coverage for over 300,000 stars, from the red-giant branch (RGB) down to the white dwarfs (WDs), provides the best chance yet to understand the multiple-population phenomenon in any GC. A preliminary analysis of the color-magnitude diagrams in different bands already allows us to identify more than 10 distinct sequences. We will make the full catalog of 15-band photometry and proper motions available to the community within 6 months of starting this project. We will then be the first to exploit this tremendous resource. The science we will address includes: (1) identifying all the sequences and tying them together, from the main sequence up to the RGB; (2) continuing the search for a central massive object; (3) examination of the WD sequence for any manifestations of multiple-populations; and (4) searching for cataclysmic variables and He WDs.

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