TITLE: GCN CIRCULAR NUMBER: 36078 SUBJECT: GRB 240411B: CrAO/ZTSh optical observations DATE: 24/04/13 07:42:11 GMT FROM: Alexei Pozanenko at IKI, Moscow <grb.alex@gmail.com> N. Pankov (HSE,IKI), V. Rumyantsev (CrAO), A. Pozanenko (IKI), S. Belkin (IKI) report on behalf of IKI GRB FuN: We observed the field of GRB 240411B (Parsotan et al., GCN 36063; Goad et al., GCN 36065; D'Avanzo et al., GCN 36071; Lien et al., GCN 36072) with ZTSh 2.6m telescope of CrAO observatory starting on 2024-04-11 (UT) 21:18:47. We detect optical afterglow (Izzo et al. GCN 36064; Schneider et al. GCN 36067; Ror et al. GCN 36069; Ugarte Postigo et al. GCN 36074; Aryan et al. GCN 36077). Preliminary photometry of the afterglow in a combined image is following Date UT start t-T0 Filter Exp. OT err UL(3sigma) (mid, days) (s) 2024-04-11 21:18:47 0.283257 R 60*120 22.40 0.25 22.8 The photometry is based on several nearby USNO-B1.0 (R2) stars USNO-B1.0 View this GCN Circular online at https://gcn.nasa.gov/circulars/36078. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...