TITLE: GCN CIRCULAR NUMBER: 5066 SUBJECT: GRB 060502B: MDM Optical Observation DATE: 06/05/03 09:38:13 GMT FROM: Jules Halpern at Columbia U. J. P. Halpern (Columbia U.) and N. Mirabal (U. Michigan) report: "We observed the location of Swift short GRB 060502B (Troja et al., GCN 5055) in the R band on the MDM 1.3m telescope starting on May 03 08:22 UT, 15 hours after the trigger. A summed 45 minute exposure has a limiting magnitude of R~23.5. To this limit, there is a single object in the refined XRT error circle of Troja et al. (GCN 5063), at coordinates (J2000) 18h 35m 45.89s +52d 37' 56.2" (+/- 1") Its magnitude is R = 21.6 +/- 0.1, calibrated with Landolt standard stars, and it appears unresolved in seeing of 1.7". Further optical observations are encouraged. This message may be cited."