TITLE: GCN CIRCULAR NUMBER: 6280 SUBJECT: GRB 070412: Gemini/GMOS afterglow candidate DATE: 07/04/12 07:23:34 GMT FROM: Edo Berger at Carnegie Obs E. Begrer (Carnegie) reports on behalf of a larger collaboration: "We observed the XRT error circle of GRB 070412 (GCN 6273) with GMOS on the Gemini-north telescope for a total of 360 sec in i-band starting on 2007 Apr 12.229 UT (4 hr after the burst). Within the XRT error circle we find a single faint object with i=23.9+/-0.2 mag (using the zeropoint on the GMOS website) located at: RA = 12:06:10.585 DEC = +40:08:24.83 (J2000) with an uncertainty of about 0.2". This position is 3.2" away from the center of the XRT error circle (GCN 6273) and 2.1" away from the I-band source discussed in GCN 6279. The non-detection of an object at this position in the R-band to a limit of 24 mag at t=1 hr (GCN 6276) indicates that this object (if it is the afterglow) is red, with R-I ~ 1.6 mag for a fading rate of t^-1."