GCN Circular 45515
Subject
GRB 260903A: SAO RAS optical observations
Event
Date
2026-09-04T15:01:32Z (13 hours ago)
From
Alexander Moskvitin at SAO RAS <mosk@sao.ru>
Via
email
A. Moskvitin (SAO RAS), O. Spiridonova (SAO RAS), A. Pozanenko (IKI),
A. Volnova (IKI), N. Pankov (IKI) report on behalf of GRB follow-up team
We observed the field of the GRB 260903A discovered by the SVOM
(Brunet et al., GCN 45499), also followed by EP (Li et al., GCN 45510)
with the Zeiss-1000, 1-m SAO RAS telescope + new CCD photometer.
A set of 16 x 300 sec images in Rc band were obtained
on September 3, 19:58:07--21:32:51 (mid. time = 8.1358 hours).
The OT (Li et al., GCN 45504; Saccardi et al., GCN 45505; Malesani
et al., GCN 45508; Russeil et al., GCN 45509) 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)
2026-09-03 19:58:07 0.33899 16*300 Rc 22.45 +/- 0.09 24.0
The preliminary photometry (Vega) is based on nearby SDSS stars
(Lupton 2005 transformation) and not corrected for Galactic extinction.
_____________________________________________
Alexander Sergeevich Moskvitin, Ph. D., researcher,
Optical Transient Physics Laboratory (#523), SAO RAS,
369167, Nizhnij Arkhyz, Karachai-Cherkessia, Russia,
+7(928)3946958, mosk@sao.ru