0 Assigned ID: 2082 ----- Attempting Submission 1 (Sat Mar 02 00:55:15 GMT 2013) ----- HST Phase I Proposal 2082 (lens3b-prop.pdf.apt) successfully submitted. ----- Attempting Submission 2 (Sat Mar 02 00:57:35 GMT 2013) ----- Approximately 12,000 gravitational microlensing events have been discovered through ground-based monitoring. Although observations of gravitational lensing events have the potential to provide measurements of the mass of the lens, only a handful of mass measurements have actually been made. If the lens-source pair can be resolved in images taken years prior to or after the event, and if the distance to the lens can be estimated, then information derived from the event light curve can be employed to measure the lens mass, an approach first attempted and verified through HST observations of the field containing the MACHO-LMC-5 event. We propose the first systematic mining of hundreds of HST images taken of the fields containing 116 recorded microlensing events. In each case, we will either derive the gravitational mass of the lens, or else place meaningful limits on a combination of its mass and distance from us. RESOLVED STELLAR POPULATIONS Default Medium false false false false false SUPPORTED