TITLE: GCN CIRCULAR NUMBER: 42539 SUBJECT: GRB 251103A: BOOTES-2/TELMA optical afterglow DATE: 25/11/03 06:11:34 GMT FROM: Alberto Castro-Tirado at Inst.de Astro. de Andalucia M. Gritsevich (Univ. if Helsinki), E. Fernandez-Garcia, A. J. Castro-Tirado, M. D. Caballero-Garcia, R. Sanchez-Ramirez, I. Perez-Garcia, S.-Y. Wu, S. Guziy (IAA-CSIC), C. Perez del Pulgar, A. Castellon, (Univ. de Malaga), Y.-D. Hu (GXU), M. Jelinek (ASU-CAS, Czech Rep.) and R. Fernandez-Munoz (IHSM/UMA-CSIC), on behalf of a larger collaboration, report: Following the detection of GRB 2451103A by SVOM (Hu et al. GCNC 42534), the 0.6m BOOTES-2/TELMA robotic telescope at IHSM La Mayora (UMA-CSIC) in Algarrobo Costa (Malaga, Spain) pointed to the burst position on Nov 3 at 04:49:21 UT (i.e. 180s after trigger). In the first 60s image we clearly detected a new bright optical source, at coordinates (J2000) = 09:47:21.40 + 16:07:21.7 (+/- 0.5”), which we propose to be the optical afterglow to GRB 251103A, consistent with the source reported by the NOT (Shneider et al. GCNC 42537). Preliminary magnitude is 15.