TITLE: GCN CIRCULAR NUMBER: 41024 SUBJECT: GRB 250704B / EP250704a: Mondy and AbAO optical observations DATE: 25/07/08 12:26:15 GMT FROM: Alexei Pozanenko at IKI, Moscow <grb.alex@gmail.com> A. Volnova (IKI), A. Pozanenko (IKI), E. Klunko (ISTP), R. Ya. Inasaridze (AbAO), N. Pankov (HSE) report on behalf of GRB IKI FuN: We observed the field of the EP250704a (Li et al., GCN 40941) also detected by SVOM (GRB 250704B; Wang et al., GCN 40940) with AZT-33IK telescope of Mondy observatory in R-filter on 2025-07-05 and with AS-32 telescope of Abastumani observatory on 2025-07-05. The optical afterglow (Li et al., GCNs 40941; Schneider et al., GCN 40942; Malesani et al., GCN 40945; Brivio et al., GCN 40947; Evans et al., GCN 40951; Perez-Garcia et al., GCN 4957; Gillanders et al., GCN 40958; Xin et al., GCN 40960; Mohan et al., GCN 40962; Moskvin et al., GCN 40963; Liu et al., GCN 40965; An et al., GCN 40966; Yang et al., GCN 4970; Martin-Carillo et al., GCN 40971; Frederiks et al., GCN 40972,Malte Busmann et al., GCN 40974, Li et al., GCN40975, Li et al., GCN 40986; An et al., GCN 40993; Wang et al., GCN 40999). We detect the afterglow on 2025-07-05. Preliminary photometry of a stacked image is the following Date UT start t-T0 Exp. Filter OT Err. UL(3sigma) Tel. (mid, days) (s) 2025-07-05|16:34:49| 1.36693| 30*120 |R|21.06 |0.05| 22.9 |AZT-33IK 2005-07-06|19:39:17| 2.51241| 52*60 |R|n/d |- | 21.2 |AS-32 The photometry is based on nearby reference stars from PS1 (Lupton transformations) RA Dec R_Lupton 20:03:37.87 +12:01:59.6 17.385 20:03:26.50 +12:02:18.5 17.436 20:03:24.72 +11:59:09.1 16.41 View this GCN Circular online at https://gcn.nasa.gov/circulars/41024. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...