TITLE: GCN CIRCULAR NUMBER: 35572 SUBJECT: GRB 240118A: AbAO optical upper limit DATE: 24/01/19 01:25:42 GMT FROM: Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru> N. Pankov (HSE, IKI), A. Pozanenko (IKI), R. Ya. Inasaridze (AbAO), S. Belkin (IKI) report on behalf of IKI GRB FuN: We observed the field of Fermi LAt localization of GRB 240118A (Bissaldi, GCN 35560) and detected also Fermi GBM (Fermi GBM team, GCN 35558; Hamburg, GCN 35563), NuSTAR (Grefenstette, GCN 35564), Swift BAT (DeLaunay, GCN 35568), and Konus-Wind (Frederiks, GCN 35567) with AS-32 telescope of Abastumani observatory (AbAO) in R-filter starting on 2024-01-18 (UT) 16:47:55. No optical candidate is detected in the LAT localization area (Bissaldi, GCN 35560). Preliminary photometry of the filed is following Date UT start t-T0 Filter Exp. OT Err. UL(3sigma) (mid, days) (s) 2024-01-18 16:47:55 0.625069 R 40*60 n/d n/d 17.4 The photometry is based on nearby USNO-B1.0 stars. View this GCN Circular online at https://gcn.nasa.gov/circulars/35572. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...