TITLE: GCN GRB OBSERVATION REPORT NUMBER: 5077 SUBJECT: GRB 060502b: Second epoch Gemini observations DATE: 06/05/06 02:43:27 GMT FROM: Paul Price at IfA,UH P.A. Price (IfA, Hawaii), E. Berger (OCIW), D.B. Fox (Penn State), S.B. Cenko and A. Rau (Caltech) report on behalf of a larger collaboration: We have obtained a second epoch of imaging with the Gemini North telescope of the XRT localisation of the short/hard GRB 060502B (GCN #5063). The observations commenced at 2006 May 4.43 UTC (1.7 days after the GRB), and consisted of 5 x 300 sec exposures in r'. These observations have better seeing and depth than our first epoch observation (2006 May 3.43 UTC, 0.7 days after the GRB; GCN #5071). Image subtraction does not reveal any variable sources within the XRT error circle. In particular, the galaxy ("G1") and source ("S1") identified in our previous observations have not appreciably changed in brightness. These observations place a limiting magnitude of any optical afterglow in our first epoch observation of approximately R ~ 24.3 mag, based on assuming R=17.5 mag for USNO-B1 star 426-035230 (RA,Dec = 278.92572,52.61611). We identify in the second epoch image an additional faint source ("S2") at R ~ 25.8 mag in the error circle at approximate coordinates: 18:35:45.86 +52:37:50.0 J2000 An image of the field is available at: http://www.ifa.hawaii.edu/~price/grb060502b.gif Note that the magnitude of the faint galaxy ("G1") in GCN #5071 is measured to be R ~ 23.8 mag in our first epoch observation, using the above calibration, consistent with the observation of Halpern & Mirabal (GCN #5072). We apologise for any inconvenience this error may have caused. We thank the Gemini North observing team for obtaining these observations.