GCN Circular 46263
Subject
GRB 261113A: Mondy and AbAO optical observations
Event
Date
2026-11-14T06:17:27Z (a day ago)
From
Alexander Moskvitin at SAO RAS <mosk@sao.ru>
Via
email
A. Moskvitin (SAO), A. Pozanenko (IKI), E. Klunko (ISTP),
R. Ya. Inasaridze (AbAO), A. Volnova (IKI), N. Pankov (IKI),
O. Spiridonova (SAO) report on behalf of IKI-GRB-FuN
and SAO GRB follow-up team.
We observed the field of the GRB 261113A (Saccardi et al., GCN 46244)
at the redshift of z = 3.580 (Saccardi et al., GCN 46261)
with the 1.5-m telescope AZT-33IK of Sayan Solar Observatory (Mondy)
and AS-32 telescope of Abastumani Observatory (AbAO) started (UT)
2026-11-13T15:06:44 and 2026-11-13T17:37:43 respectively.
The OT (Lei et al., GCN 46248; Li et al., GCN 46249; Yin et al.,
GCN 46250; Chen et al., GCN 46251; Wu et al., GCN 46252; Zhao et al.,
GCN 46253; Li et al., GCN 46254; Saikia et al., GCN 46256; Adami et al.,
GCN 46257; Gress et al., GCN 46258; Izzo et al., GCN 46259; Saccardi et
al.,
GCN 46261; Maksut et al., GCN 46262; also observed in NIR: Lin et al.,
GCN 46247; Brivio et al., GCN 46260) is clearly detected in our stacked
images. The results of some stacked epochs are as follows.
Date UT start t-T0 Exp, Filter Obj Err UL Telescope
(mid,h) (n*s) (3sigma)
2026-11-13T15:06:44 0.67833 10*60 R 19.04 +/- 0.02 22.1 AZT-33IK
2026-11-13T15:26:45 1.01208 10*60 R 19.18 +/- 0.04 21.6 AZT-33IK
2026-11-13T15:46:56 1.34847 10*60 R 19.35 +/- 0.03 22.0 AZT-33IK
2026-11-13T16:09:31 1.72486 10*60 R 19.50 +/- 0.04 22.0 AZT-33IK
2026-11-13T16:29:33 2.06708 10*60 R 19.76 +/- 0.13 20.9 AZT-33IK
2026-11-13T16:50:35 2.40931 10*60 R 19.75 +/- 0.05 22.0 AZT-33IK
2026-11-13T17:37:43 3.63917 40*60 R 20.48 +/- 0.17 21.3 AS-32
This preliminary photometry (Vega) is based on nearby SDSS stars
(Lupton 2005 transformation) and not corrected for Galactic extinction.
Based on our data, it can be suggested that there is a jet break
in the light curve, occurring between 3 and 4 hours after the onset of the
burst.