GCN Circular 35172
Subject
GRB 231117A: Mondy optical observations
Date
2023-11-23T23:07:40Z (10 months ago)
From
Alexei Pozanenko at IKI, Moscow <apozanen@iki.rssi.ru>
Via
legacy email
N. Pankov (HSE, IKI), A. Pozanenko (IKI), E. Klunko (ISTP), S. Belkin (IKI) report on behalf of GRB IKI FuN:
We observed the field of GRB 231117A (Laha et al., GCN 35071; Navaneeth et al., GCN 35072; Beardmore et al., GCN3574; Cattaneo et al., GCN 35075; Svinkin et al., GCN 35079; Cheung et al., GCN 35081; Dafcikova et al., GCN 53095; Busman et al. GCN 35138; O'Connor et al., GCN 35139; Watson et al., GCN 35153, Kuin et al., GCN 35154; Dichiara et al., GCN 35160; Fong et al., GCN 35163) with AZT-33IK telescope of Mondy observatory in R-filter on 2023-11-17, 2023-11-18 and 2023-11-20. Using image subtraction and the image on 2023-11-20 as a template we obtained preliminary photometry of the optical transient
Date UT start t-T0 Exp. Filter OT Err.
(mid, days) (s)
2023-11-17 11:45:33 0.38349 30x120 R 21.00 0.16
2023-11-18 12:09:46 1.41142 46x120 R 21.59 0.16
The photometry is based on nearby USNO-B1.0 R2 stars. The index of power law (t-T0)^-alpha between the two epochs is alpha = 0.8 (+0.13 -0.2).
However, photometry may be biased due to the template contamination by a still decaying optical transient, so we caution against using this index for any physical assessments.