TITLE: GCN CIRCULAR NUMBER: 15917 SUBJECT: GRB 140304A: Mondy optical observations DATE: 14/03/04 15:02:59 GMT FROM: Alexei Pozanenko at IKI, Moscow A.Volnova (IKI), A. Pozanenko (IKI), I. Korobtsev (ISTP), E. Klunko (ISTP), M. Eselevich (ISTP), report on behalf of larger GRB follow-up collaboration: We observed the field of GRB 140304A (Evans et al., GCN 15915) with AZT-33IK telescope of Mondy observatory starting on Mar. 04 (UT) 13:54:10, i.e. ~0.5 hour after burst trigger. In the first images of 60 s exposure we clearly detected afterglow of GRB 140304A reported by Gorbovskoy et al. (GCN 15914) and Xu et al. (GCN 15916). Preliminary photometry of the fading afterglow is following: date UT start t-T0 Exp. Filter OT (mid, days) (s) 2014-03-04 13:54:10 0.02406 6*60 R 20.29 ± 0.17 The photometry is based on reference stars SDSS-DR9, (R mag, transformation by Lupton 2005): N SDSS_id R(Lupton) err J020233.12+332550.3 15.665 0.012 J020219.91+332738.5 14.785 0.012