TITLE: GCN CIRCULAR NUMBER: 44353 SUBJECT: GOTO26djh/AT2026jpw: CrAO and Mondy optical observations of the transient DATE: 26/04/20 06:51:39 GMT FROM: Nicolai Pankov at IKI <colinsergesen@gmail.com> N. Pankov (IKI), V. Rumyantsev (CrAO), E. Klunko (ISTP), A. Pozanenko (IKI), A. Volnova (IKI) report on behalf of IKI-GRB-FuN: We continued 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; Pankov et al., GCN 44316) in the R band with the Shajn 2.6-meter telescope (ZTSh) of the Crimean Astrophysical Observatory (CrAO) and the 1.5-meter AZT-33IK telescope of the Sayan Solar Observatory (Mondy). The observations began on 2026-04-16 20:53 UT, i.e. ~2.92 days since GOTO detection at CrAO and on 2026-04-18 14:47 UT (~4.67 days since GOTO detection) at Mondy. The series of 38x120s exposures were taken by ZTSh/CrAO and 35x120s exposures were taken by AZT-33IK/Mondy. The optical counterpart is clearly detected in the co-add image from CrAO, but not detected by AZT-33IK. The preliminary photometry and observation details are provided below: Date UT start t-T0 Exp. Filter OT Err. UL(3sigma) Telescope/Site (mid, days) (s) 2026-04-16 20:53:30 2.92638 38x120 R 22.11 0.02 23.7 ZTSH/CrAO 2026-04-18 14:47:18 4.66999 35x120 R n/d n/d 22.8 AZT-33IK/Mondy 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/44353. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...