TITLE: GCN CIRCULAR NUMBER: 45361 SUBJECT: GRB 260809A: SAO RAS optical observations DATE: 26/08/12 11:58:37 GMT FROM: Alexander Moskvitin at SAO RAS <mosk@sao.ru> A. Moskvitin (SAO RAS), N. Pankov (IKI), A. Pozanenko (IKI), A. Volnova (IKI), O. Spiridonova (SAO RAS) report on behalf of GRB follow-up team We observed the field of the GRB 260809A discovered by the SVOM (Brunet et al., GCN 45331), also detected by EP-FXT (Sun et al., GCN 45344) with the Zeiss-1000, SAO RAS 1-m telescope + CCD photometer on 2026-08-09T23:20:36--2026-08-10T00:49:19 UT (t_mid = 9.1234 hours). The OT (Li et al., GCN 45336; Adami et al., GCN 45338; Rajabov et al., GCN 45339; Izzo, Saccardi and Corcoran, GCN 45340; Basa et al., GCN 45342) is clearly detected in our stacked image. Details of the observation are the following. Date, UTstart, t-T0, Exp., Filter, Mag, Err., UL (mid,d) (n*s) (3-sigma) 2026-08-09 23:20:36 0.38014 14*300 Rc 22.60 +/- 0.17 23.4 This preliminary photometry (Vega) is based on nearby SDSS stars (Lupton 2005 transformation) and not corrected for Galactic extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/45361. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...