GCN Circular 42964
Subject
EP251202a/GRB 251202A: KAIT optical observations
Event
Date
2025-12-02T20:38:22Z (12 hours ago)
From
Weikang Zheng at UC Berkeley <weikang@berkeley.edu>
Via
email
WeiKang Zheng (UCB), Xuhui Han (NAOC), Pinpin Zhang (NAOC) and
Alexei V. Filippenko (UCB) report on behalf of the KAIT GRB team:
The 0.76-m Katzman Automatic Imaging Telescope (KAIT), located at
Lick Observatory, observed the field of EP251202a/GRB 251202A
(Zhang et al., GCN 42937; Liang et al., GCN 42946; Fermi GBM team,
GCN 42933; Bala et al., GCN 42957) from 6.29 to 10.59 hours
after the burst. A set of 60s clear (roughly R) filter images
were obtained. We clearly detected the optical afterglow (Li
et al., GCN 42934; Zhu et al., GCN 42939; O’Neill et al., GCN
42947; Quirola-Vasquez et al., GCN 42948; Kuin et al., GCN 42956)
in our coadd images. We measure its brightness decayed from
18.7 +/- 0.1 mag (Vega; mid time 6.30 hours) to 19.3 +/- 0.2 mag
(mid time of 10.55 hours) with a power-law decay index of 1.07.