TITLE: GCN CIRCULAR NUMBER: 44316 SUBJECT: GOTO26djh/AT2026jpw: ZTSh R,I bands observations of the transient DATE: 26/04/16 15:00:15 GMT FROM: Nicolai Pankov at IKI <colinsergesen@gmail.com> N. Pankov (IKI), V. Rumyantsev (CrAO), A. Pozanenko (IKI), A. Volnova (IKI) report on behalf of IKI-GRB-FuN: We performed optical observations of the field of AT2026jpw (O'Neill et al., GCN 44301; Corcoran et al., GCN 44303; Moskvitin and Spiridonova, GCN 44304; Xu et al., GCN 44305; The COLIBRÍ team, GCN 44306; Sosnovskij et al., GCN 44309; Ma et at., GCN 44314) in the R- and I-bands with the Shajn 2.6-meter telescope (ZTSh) of the Crimean Astrophysical Observatory (CrAO). The observations began on 2026-04-15 19:17 UT, i.e. ~1.84 days since GOTO detection. The series of 15x120s exposures were taken in the R-band and 21x120s exposures were taken in the I-band. The optical counterpart is clearly detected. The preliminary photometry and observation details are provided below: Date UT start t-T0 Exp. Filter OT Err. UL(3sigma) (mid, days) (s) 2026-04-15 19:17:42 1.84388 15x120 R 21.49 0.05 23.6 2026-04-15 19:56:05 1.87469 21x120 I 21.59 0.08 23.3 The photometry is calibrated using nearby stars from USNO-B1.0 (see Moskvitin and Spiridonova, GCN 44304) and has not been corrected for the Galactic extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/44316. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...