TITLE: GCN CIRCULAR NUMBER: 12845 SUBJECT: AXP 4U 1042+61: Mondy optical observations DATE: 12/01/17 18:19:43 GMT FROM: Alina Volnova at SAI MSU A. Volnova (SAI MSU), I. Korobtsev, E. Klunko (ISTP), A. Pozanenko (IKI) on behalf of larger GRB follow up collaboration report: We observed the field of the AXP 4U 1042+61 (Swift �trigger 511611,Barthelmy et al., GCN 12829) with AZT-33IK telescope of Sayan observatory (Mondy) on Jan., 12 between (UT) 14:11:04 - 15:01:42 with a mean seeing (FWHM) of about 2.1". We took several series of 60 s exposures in R-filter. In a stacked image we do not detect any source in the XRT error circle. The photometry is based on the USNO-B1.0 1517-0055618 star (RA=01 46 21.83, Dec=+61 45 56.9) assuming R2=18.17. UT_start, � t-t0, Filter, Exposure, � OT � � � uplim � � � � � � � d s � � � � � � �� � � � �3 sigma 14:11:04 �0.06753 R 50x60 �� � �n/d � � �22.3