TITLE: GCN CIRCULAR NUMBER: 13236 SUBJECT: GRB 120404A: optical observations in Mondy observatory DATE: 12/04/08 14:58:38 GMT FROM: Alexei Pozanenko at IKI, Moscow A.Volnova (SAI MSU), E. Klunko (ISTP), A. Pozanenko (IKI) on behalf of larger GRB follow up collaboration report: We observed the field of the Swift GRB 120404A (Stratta et al., GCN 13208) with AZT-33IK telescope of Sayan observatory (Mondy). We took several images in R-filter of 60 s exposure on Apr. 04, starting (UT) 14:31:21. We clearly detected optical afterglow (Stratta et al., GCN 13208; Guidorzi et al., GCN 13209) in single images. A preliminary photometry of combined images is based on nearby USNO-B1.0 stars: t_start, t-t0 (mid), filter exp., OT, err (UT) d s 14:31:21 0.07142 R 5x60 18.24 0.05 14:37:26 0.07564 R 5x60 18.36 0.04 14:42:30 0.07916 R 5x60 18.40 0.05 14:47:34 0.08268 R 5x60 18.36 0.07 14:52:37 0.08619 R 5x60 18.59 0.07 14:58:42 0.09041 R 5x60 18.59 0.04 15:03:46 0.09393 R 5x60 18.77 0.12 15:08:50 0.09920 R 10x60 18.76 0.06 15:19:58 0.10694 R 10x60 18.95 0.06 15:30:06 0.11432 R 10x60 18.94 0.08 15:41:14 0.12171 R 10x60 19.00 0.08 15:51:21 0.12908 R 10x60 19.30 0.09 Our photometry suggests bumpy light curve of the afterglow during our observations.