GCN Circular 42785
Subject
EP251118a / GRB 251118C: SAO RAS optical observations
Event
Date
2025-11-20T21:15:01Z (a day ago)
From
Alexander Moskvitin at SAO RAS <mosk@sao.ru>
Via
Web form
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.