TITLE: GCN CIRCULAR NUMBER: 6987 SUBJECT: GRB 071025: ROTSE-III Detection of Optical Counterpart DATE: 07/10/25 04:37:51 GMT FROM: Eli Rykoff at U of Michigan/ROTSE E.S. Rykoff (UCSB), F. Yuan (U Mich), B. E. Schaefer (Louisiana State), H. Swan (U Mich), R. Quimby (Caltech), report on behalf of the ROTSE collaboration: ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 071025 (Swift trigger 295301, GCN 6986). The first image was at 04:10:14.0 UT, 80.3 s after the burst (6.0 s after the GCN notice time). The unfiltered images are calibrated relative to USNO A2.0. We detect a 19.2 magnitude, fading source with coordinates: 23:40:17.19 +31:46:42.64 (J2000), with positional uncertainty of 1" or better start UT mag mlim(of image) ---------------------------------- 04:16:27.1 19.2 18.6 This source is not visible in DSS (second epoch), 2MASS or the MPChecker database. A jpeg image is available at http://www.rotse.net/images/gsb295301_3b021-030_key.jpg Continuing observations are in progress.