TITLE: GCN CIRCULAR NUMBER: 9828 SUBJECT: GRB 090817: aphotometry of USNO-B1.0 341-0096763 DATE: 09/08/19 21:51:06 GMT FROM: Alexei Pozanenko at IKI, Moscow V. Rumyantsev (CrAO), A. Pozanenko (IKI), M. Andreev (Terskol Branch of Institute of Astronomy) report on behalf of larger GRB follow-up collaboration: We report a photometry of the USNO-B1.0 object 341-0096763 in the XRT error circle of the X-ray afterglow (Evans et al., GCN 9819, GCN 9825) of the INTEGRAL GRB 090817 (Beckmann et al., GCN 9815). The observations took place with Shajn telescope of CrAO on Aug.17 (Rumyantsev et al., GCN 9826). The photometry is based on the reference star USNO B1.0 1341-0096766 (04 15 48.35 +44 08 07.7) assuming R = 17.54, only statistical errors are quoted. Upper limits are presented for isolated object. To make any conclusion about variability of the star or the presence in the tail of the star other possible source we are planning second epoch observation. Date Time start (UT) Upper_Limit R_mag 2009-08-17 01 09 36.45 21.5 19.33 +/-0.05 2009-08-17 01 10 40.62 21.5 19.38 +/-0.05 2009-08-17 01 13 23.49 21.7 19.43 +/-0.04 2009-08-17 01 14 27.16 21.7 19.32 +/-0.04 2009-08-17 01 15 30.91 21.8 19.35 +/-0.04 2009-08-17 01 16 34.72 21.9 19.46 +/-0.04 2009-08-17 01 17 38.27 21.9 19.40 +/-0.04 2009-08-17 01 18 41.93 21.9 19.44 +/-0.04 2009-08-17 01 19 45.99 21.7 19.39 +/-0.04 2009-08-17 01 20 49.53 21.7 19.37 +/-0.04 2009-08-17 01 21 53.11 21.8 19.45 +/-0.04 2009-08-17 01 22 58.16 21.7 19.40 +/-0.04 2009-08-17 01 24 01.75 21.8 19.28 +/-0.04 2009-08-17 01 25 05.64 21.8 19.45 +/-0.04 2009-08-17 01 26 09.20 21.8 19.46 +/-0.04 2009-08-17 01 27 12.86 21.8 19.39 +/-0.04 2009-08-17 01 28 16.41 21.8 19.38 +/-0.04 2009-08-17 01 29 22.52 21.6 19.38 +/-0.05 2009-08-17 01 30 26.12 21.6 19.39 +/-0.05 2009-08-17 01 31 29.63 21.6 19.38 +/-0.05 2009-08-17 01 32 33.37 21.7 19.33 +/-0.04 2009-08-17 01 33 38.37 21.6 19.39 +/-0.05 2009-08-17 01 34 42.08 21.6 19.38 +/-0.05 2009-08-17 01 35 45.77 21.6 19.42 +/-0.05 2009-08-17 01 36 49.51 21.5 19.46 +/-0.06 2009-08-17 01 37 53.18 21.4 19.34 +/-0.05 2009-08-17 01 38 56.70 21.3 19.55 +/-0.08 2009-08-17 01 40 00.31 21.3 19.44 +/-0.07 2009-08-17 01 41 06.39 21.2 19.30 +/-0.07 2009-08-17 01 42 12.89 21.2 19.47 +/-0.08 2009-08-17 01 43 16.53 21.1 19.41 +/-0.08 2009-08-17 01 44 20.34 21.1 19.43 +/-0.08 2009-08-17 01 45 24.13 20.9 19.41 +/-0.10 2009-08-17 01 46 28.68 20.9 19.42 +/-0.10 2009-08-17 01 47 32.26 20.7 19.29 +/-0.11 2009-08-17 01 48 35.81 20.7 19.52 +/-0.13