TITLE: GCN CIRCULAR NUMBER: 15893 SUBJECT: GRB 140226A/iPTF14yb: Mondy optical observations DATE: 14/02/28 16:22:51 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 transient iPTF14yb (Cenko et al., GCN 15883, Beardmore et al., GCN 15884, 15891) of possible GRB 140226A (Hurley et al., GCN 15888) with AZT-33IK telescope of Mondy observatory on Feb. 27 between (UT) 18:59:34 - 19:59:36. On a stacked R-filter image of 30 x 120 s we marginally detected iPTF14yb source with S/N ~2, and photometry of the source R = 23.0 at Feb. 27.81221 (mid). The photometry is based on SDSS J144600.66+145826.2 star assuming R(Lupton transformation)= 17.624 +/- 0.018