TITLE:   GCN CIRCULAR
NUMBER:  46240
SUBJECT: GRB 261026A: CrAO ZTSh optical observations
DATE:    26/11/12 17:26:34 GMT
FROM:    Alexander Moskvitin at SAO RAS <mosk@sao.ru>

A. Moskvitin (SAO), V. Rumyantsev (CrAO), A. Pozanenko (IKI),
A. Volnova (IKI), N. Pankov (IKI) report on behalf of SAO GRB
follow-up team and IKI GRB-FuN.

We observed the field of the GRB 261026A discovered by SVOM
(Goto et al., GCN 46030; Xie et al., GCN 46068), also detected
by EP-FXT (Jiang et al., GCN 46058) with the Shajn 2.6-meter
telescope (ZTSh) of the Crimean Astrophysical Observatory (CrAO)
on 2026-11-10T16:05:36--2026-11-10T17:35:39 UT.

The OT (Dornic et al., GCN 46033; Zheng et al., GCN 46034; Wu et al.,
GCN 46035; Li et al., GCN 46046; Morín-González et al., GCN 46048;
Coyo et al., GCN 46054; Moskvitin et al., GCN 46062; Li et al.,
GCN 46063; Moskvitin et al., GCN 46110; also observed in NIR:
Mohan et al., GCN 46041; Shi et al., GCN 46047; Manyan et al.,
GCN 46064) is detected in our stacked frame.
Details of the observation are the following.

Date        UT start  t-T0      Exp,    Filter Obj       Err  UL
                     (mid,days) (n*s)                         (3sigma)
2026-11-10  16:05:36 15.44515   43*120  R      23.28 +/- 0.25 24.6


This preliminary photometry (Vega) is based on nearby SDSS stars
(Lupton 2005 transformation) and not corrected for Galactic extinction.