TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4113 SUBJECT: GRB 050502b: Optical limit DATE: 05/10/19 04:41:38 GMT FROM: Ken ichi Torii at RIKEN K. Torii (Osaka U.) reports on behalf of the ART collaboration: The error region of the bright GRB 050502b (Falcone et al. GCN 3330) was observed by the 14 inch Automated Response Telescope. Ic band imaging was started at 2005 May 2 10:19:30 UT (54 minutes after the burst) and 60s exposure was repeated. The optical afterglow (Rich et al. GCN 3338) is not detected in our frames and the following 3-sigma upper limit is derived for a stacked image. ------------------------------------------ StartUT-EndUT Filter Limit Exposure ------------------------------------------ 10:55:59-13:00:20 Ic >18.6 87x60s ------------------------------------------