TITLE: GCN CIRCULAR NUMBER: 42072 SUBJECT: GRB 251003A: 1.5m OSN afterglow candidate DATE: 25/10/03 03:06:40 GMT FROM: Alberto Castro-Tirado at Inst.de Astro. de Andalucia F. J. Aceituno, R. Sanchez-Ramirez A. J. Castro-Tirado, S. Guziy, M.D. Caballero-Garcia, S.-Y. Wu and I. Perez-Garcia (IAA-CSIC), and Y.-D. Hu (GXI), on behalf of a larger collaboration, report: Following the detection of GRB 251003A by both Fermi (Fermi team, GCNC 42069) and Swift (Beardmore et al. GCNC 42070), we obtained a 300s exposure image (I-band) with the 1.5m OSN telescope in Sierra Nevada (Granada, Spain) starting on Oct 3 (02:34 UT, i.e. 36 min post burst). At the enhanced X-ray position (Evans et al. GCNC 42071) we identify an optical source with a preliminary magnitude of 21, which we propose to be the afterglow to GRB 251003A. Further observations are being gathered.