TITLE: GCN CIRCULAR NUMBER: 18962 SUBJECT: GRB 160131A: Khureltogot optical observations DATE: 16/01/31 20:22:21 GMT FROM: Alexei Pozanenko at IKI E. Mazaeva (IKI), S. Schmalz (AIP), N. Tungalag (Research Center of Astronomy and Geophysics MAS), A. Volnova (IKI), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger GRB follow-up collaboration: We observed the field of Swift GRB 160131A (Page et al., GCN Page) with ORI-40 telescope of Khureltogot observatory on Jan., 31 from(UT) 11:14 up to (UT) 16:34. We obtained several unfilteed images. We clearly detect optical afterglow (Page et al., GCN 18951; Yurkov et al., GCN 18952; Guidorzi et al., GCN 18953; Xin et al., GCN 18954; Xin et al., GCN 18955; Watson et al., GCN 18956). Preliminary photometry of the afterglow in the first images is following Date UT start t-T0 Filter Exp. OT Err (mid, days) (s) 2016-01-31 11:14:41 0.12106 20 16.43 0.10 2016-01-31 11:27:26 0.13015 60 16.49 0.04 2016-01-31 11:28:30 0.13089 60 16.51 0.04 2016-01-31 11:29:35 0.13164 60 16.50 0.04 2016-01-31 11:30:39 0.13238 60 16.52 0.05 2016-01-31 11:31:43 0.13388 60 16.61 0.05 2016-01-31 11:33:52 0.13462 60 16.46 0.04 2016-01-31 11:34:57 0.13537 60 16.53 0.05 2016-01-31 11:36:01 0.13611 60 16.58 0.05 2016-01-31 11:37:06 0.13686 60 16.62 0.05 2016-01-31 11:38:10 0.13760 60 16.56 0.04 2016-01-31 11:39:14 0.13834 60 16.58 0.04 2016-01-31 11:40:18 0.13909 60 16.57 0.04 Photometry is based on nearby USNO B1.0 stars, R2 magnitude.