Assigned ID: 78 ----- Submission 1 (Thu Jan 20 17:33:06 GMT 2005) ----- We are searching for flares expected to occur when a supermassive black hole (SMBH) tidally disrupts a star from its host galaxy and accretes the captured gas. The expected event rate for complete stellar disruptions of main sequence stars is 2.2 x 10^-4 (L/10^10Lo)^-0.30 per galaxy per year, according to calculations recently published by one of us. The flares should be easy to detect, even for partial disruptions, if anywhere near the Eddington luminosity as expected theoretically. The HST archives are currently the best resource for finding flares. HST's resolution allows fitting of a host and nuclear component on galaxies that could barely be resolved from the ground. In the first of two methods, we will compare the same galaxies at two different HST imaging epochs: Approximately 30 flares are expected in about 16,000 galaxies in WFPC2 archival images taken at two or more epochs. In a second method, we compare about 200,000 galaxies in WFPC2 and ACS archival single-epoch images with subsequent Sloan images. This is expected to lead to the discovery of ~ 60 flares. ACS provides fewer two-epoch observations but a comparable database for the one-epoch method. Taken together, we estimate 90 detectable flares.

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