TITLE: GCN CIRCULAR NUMBER: 13853 SUBJECT: GRB 121011A: TNG optical observations DATE: 12/10/11 21:24:30 GMT FROM: Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst D. Malesani (DARK), P. D'Avanzo (INAF/OABr), A. Melandri (INAF/OABr), V. Nascimbeni (Univ. Padova), C. Padilla (INAF/TNG), report on behalf of the CIBO collaboration: We observed the optical afterglow of GRB 121011A (Racusin et al., GCN 13845) with the TNG equipped with DOLoRes. The afterglow is well detected in a single 5-min exposure, with a mean time Oct 11.829 UT (8.63 hr after the GRB). Its magnitude is R = 21.74 +- 0.06, assuming R = 17.84 for the USNO star at RA = 17:20:44.70, Dec = +41:04:52.7. The afterglow has the following coordinates (calibrated against USNO-B1 stars): RA = 17:20:51.22 Dec = +41:06:37.4 with an estimated uncertainty of 0.4".