TITLE: GCN CIRCULAR NUMBER: 11876 SUBJECT: GRB 110402A: optical observations in Mondy DATE: 11/04/04 14:33:37 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Volnova (SAI MSU), A. Pozanenko (IKI), E. Klunko (ISTP) on behalf of larger GRB follow up collaboration report: We observed the field of GRB 110402A (Ukwatta et al. GCN 11857) with AZT-33IK telescope of Sayan observatory (Mondy) on April, 2 between (UT) 13:04:22 - 14:37:38 under moderate weather condition and seeing of about 2". In a stacked image we clearly detect optical counterpart (Mundell et al. GCN 11858, Leloudas et al. GCN 11859). The position of the counterpart is (J2000) RA= 13:09:36.42 Dec= +61:15:10.35 with uncertainty of 0,4" in both coordinates. The position is 1.7" apart from initial position reported by Mundell et al. (GCN 11858). The photometry is based on the USNO B1 star 1512-0199231 assuming R= 16.71 T0+ Filter, Exposure, OT mag., UpperLimit (3 sigma) (mid, d) (s) 0.56809 R 5430 21.35 +/- 0.10 22.9 Since the position of counterpart is marginally different from initial position and the R-magnitude does not change since 251.6 minutes after burst (see Leloudas et al. GCN 11863) we can suggest that host galaxy dominates in our observations. [GCN OPS NOTE(30apr11): Per author's request, Elunko was changed to Klunko.]