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.