TITLE: GCN CIRCULAR NUMBER: 16880 SUBJECT: GRB 141004A: 1.23m CAHA optical observations DATE: 14/10/05 01:02:09 GMT FROM: Javier Gorosabel at IAA-CSIC J. Gorosabel (IAA-CSIC/UPV-EHU), S. Hellmich (DLR), S. Mottola (DLR), on behalf of a larger collaboration report: We observed the GRB 141004A (D'Elia et al. GCN 16878) field with the 1.23m CAHA telescope. The observations were done in the Ic-band starting on Oct 4.9969 UT (34.6 minutes post GRB). A preliminary analysis detects a faint optical object located at (RA, DEC)=05:06:56.17, 12:49:10.8 (+/-0.7"), so consistent with the UVOT position. We estimate a preliminary Vega magnitude of Ic~19.2, calibrated against the USNO B1.0 catalog.