TITLE: GCN CIRCULAR NUMBER: 43500 SUBJECT: EP260119a: Assy AZT-20 optical observations DATE: 26/01/22 12:09:42 GMT FROM: Alina Volnova at IKI RAS <alinusss@gmail.com> A. Volnova (IKI), A. Pozanenko (IKI), M. Krugov (FAI), N. Pankov (IKI) report on behalf of IKI-GRB-FuN: We observed the field of the EP260119a (Jiang et al., GCN 43447; GCN 43465; Cheng et al., GCN 43449) at the redshift of z ~ 5.47 (Corcoran et al., GCN 43469) with the AZT-20 telescope of Assy-Turgen observatory starting on 2026-01-20 (UT) 14:53 and taking several 60-second exposures in i' filter. In the stacked frame we detect the optical counterpart (Fortin et al., GCN 43450; GCN 43455; Eyles-Ferris et al., GCN 43452; Moskvitin and Spiridonova, GCN 43463; Liu et al., GCN 43464; Ma et al., GCN 43466; Zheng et al., GCN 43468; Corcoran et al., GCN 43469; Bochenek and Perley, GCN 43472; Pankov et al., GCNs 43476, 43499; Jin et al., GCN 43496). Preliminary photometry and observational details are the following: Date UT start t-T0 Exp. Filter Obj. Err. UL Site/Telescope (mid,days) (n*s) (3sigma) 2026-01-20 14:53:00 1.63500 63*60 i' 22.7 0.2 23.2 Assy-Turgen/AZT-20 The photometry is based on several nearby SDSS stars (i-magnitudes) and is not corrected for the Galactic extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/43500. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...