TITLE: GCN CIRCULAR NUMBER: 42785 SUBJECT: EP251118a / GRB 251118C: SAO RAS optical observations DATE: 25/11/20 21:15:01 GMT FROM: Alexander Moskvitin at SAO RAS <mosk@sao.ru> A. Moskvitin and O. Spiridonova (SAO RAS), report on behalf of GRB follow-up team We observed the field of the EP251118a discovered by Einstein Probe (Jiang et al., GCN 42749; Shi et al., GCN 42754, also detected with the other space observatories, Frederiks et al., GCN 42765; Wang et al., GCN 42766; DeLaunay et al., GCN 42770; Woolf et al., GCN 42771) with the 1-m SAO RAS telescope Zeiss-1000 equipped with the CCD-photometer. We obtained 9 x 300 sec. images Rc band on 2025.11.19T23:26:31--2025.11.20T03:08:31 (t_mid - T0 = 1.35766 d). The OT (Malesani et al., GCN 42751; An et al., GCN 42756; Belkin et al., GCN 42758; Busmann et al., GCN 42763; Francile et al., GCN 42767; Urquijo-Rodríguez et al., GCN 42773; Lee et al., GCN 42780; also detected in NIR; Yadav et al., GCN 42760) is clearly visible in our stacked image with the brightness of R = 21.24 +/- 0.07. Preliminary photometry is based on the nearby objects from SDSS (magnitudes converted with Lupton 2005 equations) and has not corrected for the Galactic extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/42785. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...