TITLE: GCN CIRCULAR NUMBER: 11707 SUBJECT: GRB 110213A: ROTSE-III Detection of Optical Counterpart DATE: 11/02/13 05:44:46 GMT FROM: Brad Schaefer at LSU W. Rujopakarn (Steward), B. E. Schaefer (Louisiana State), E.S. Rykoff (LBNL), report on behalf of the ROTSE collaboration: ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 110213A (Swift trigger 445414). The first image was at 05:17:56.7 UT, 27.1 s after the burst (0.7 s after the GCN notice time). The unfiltered images are calibrated relative to USNO A2.0. We detect a 15.8 magnitude, fading source with coordinates: 02:51:51.11 +49:16:20.57 (J2000), with positional uncertainty of 1' or better start UT mag mlim(of image) ---------------------------------- 05:17:56.7 15.8 17.0 This source is not visible in DSS (second epoch), 2MASS or the MPChecker database. Our light curve shows a beautiful rise starting 100 seconds after the Swift trigger, reaching a peak around 14.5 mag at 200 seconds after the trigger and then starting a fast decline. Continuing observations are in progress.