TITLE: GCN CIRCULAR NUMBER: 35232 SUBJECT: GRB 231129A: optical upper limit in Mondy observatory DATE: 23/11/30 11:05:26 GMT FROM: Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru> S. Belkin (IKI), E. Klunko (ISTP), A. Pozanenko (IKI), N. Pankov (IKI, HSE) report on behalf of GRB IKI FuN: We observed the field of Swift GRB 231129A (Gropp et al., GCN 35208; Mereghetti et al., GCN 35209; Zhang et al., GCN 35210) with AZT-33IK telescope of Mondy observatory in R-filter on 2023-11-29 starting (UT) 10:43:30. We do not detect any optical objects within the enhanced Swift-XRT error box (Goad et al., GCN 35220). Preliminary photometry of a stacked image is following Date UT start t-T0 Exp. Filter OT Err. UL(3sigma) (mid, days) (s) 2023-11-29 10:43:30 0.25730 33x120 R n/d n/d 23.1 The photometry is based on nearby USNO-B1.0 stars. USNO-B1.0 RA DEC R2 21:10:16.6747200 +41:33:09.000000 17.36 21:10:16.0548000 +41:32:49.822800 18.82 View this GCN Circular online at https://gcn.nasa.gov/circulars/35232. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...