TITLE:   GCN CIRCULAR
NUMBER:  16037
SUBJECT: GRB 140226A/iPTF14yb: Mondy optical observations
DATE:    14/03/25 15:11:32 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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) a possible counterpart of GRB 
140226A (Hurley et al., GCN 15888) with AZT-33IK telescope of Mondy 
observatory on Feb. 28 between (UT) 19:22:46 - 21:52:52 R-filter. On a 
stacked image of 75 x 120 s we clearly detected iPTF14yb source with a 
magnitude of R = 22.86 ± 0.17 at Feb. 28.85959 (mid) or 2.44087 days 
after GRB 140226A trigger (Hurley et al., GCN 15888).

The photometry is based on SDSS J144600.66+145826.2 star assuming
R(Lupton transformation)= 17.624 +/- 0.018.