TITLE: GCN CIRCULAR NUMBER: 14114 SUBJECT: GRB 121226A: 10.4m GTC optical observations DATE: 12/12/28 01:49:33 GMT FROM: Javier Gorosabel at IAA-CSIC A.J. Castro-Tirado, M. Jelinek, R. Sánchez-Ramírez, J.C. Tello (IAA-CSIC), J.M. González-Pérez (GTC/IAC), S. Guziy (Mykolaiv Nat. Univ.), D. Pérez-Ramírez (Univ. de Jaén), P. Ferrero (IAC), J.M. Castro Cerón (ESAC), A. Fernández-Soto (IFCA-UNICAN) and J. Gorosabel (IAA-CSIC), report: “We have obtained deep r’i’z’ images with the 10.4m GTC telescope at Observatorio del Roque de los Muchachos for GRB 121226A (Krimm et al. GCNC 14105; Baumgartner et al. GCNC 14111) starting on Dec 27.230--27.261 UT (i.e., 10.3--11.1 hr post burst). A faint object is detected at RA(J2000)=11:14:34.14, DEC(J2000)=-30:24:22.9 (0.7" error in each coordinate), consistent with the position of the X-ray afterglow (Littlejohns et al. GCNC 14112). The object shows a magnitude around r'~25. At this stage we cannot conclude whether this is the GRB 121226A optical afterglow or the underlying host galaxy.”