TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2707 SUBJECT: Optical observations of GRB/XRF 040912 = HETE 3557 DATE: 04/09/13 14:35:54 GMT FROM: Jens Hjorth at U.Copenhagen M. I. Andersen (AIP), M. Weidinger (U. Aarhus), J. Hjorth, J. P. U. Fynbo, B. L. Jensen (U. Copenhagen) report: "Using the ALFOSC at the 2.56-m Nordic Optical Telescope, La Palma, we have obtained 2 x 2 mosaic CCD images covering the HETE-2 error circle of GRB/XRF 040912 (Butler et al., GCNC 2701) on two epochs. Each pointing consists of 3 x 300 sec in the R band. Comparison of the two epochs (Sep 12.92-12.97 and Sep 13.19-13.24 2004 UT) through visual inspection and difference imaging does not reveal any sources exhibiting significant variability between the two epochs. The 3-sigma variability limit is R ~ 23.4."