TITLE: GCN CIRCULAR NUMBER: 6191 SUBJECT: GRB 070311: PAIRITEL confirmation of variability of REM candidate DATE: 07/03/11 03:47:25 GMT FROM: Josh Bloom at UC Berkeley J. S. Bloom (UC Berkeley) reports: We analyzed the stack of images of the field of GRB 070311 (Mereghetti et al. GCN 6189) obtained with the 1.3m PAIRITEL project starting 2007-03-11 02:07:17 UTC (494 second total). The source noted as a possible afterglow by Covino et al. (GCN 6190) is well detected in J and H band. A comparison to 2MASS yields a preliminary H-band magnitude of H=17.0 +/- 0.1. This is 2.7 magnitudes fainter and ~14 minutes later than the REM detection. As such, we confirm that the source noted by Covino et al. is indeed the afterglow of GRB 070311. This message may be cited.