GCN Circular 39832
Subject
EP250321a: KAIT optical observations
Event
Date
2025-03-22T05:56:29Z (7 months 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, automatically responded to EP250321a detected
by Einstein Probe (Hu et al., GCN 39800) starting at 07:05:35 UT,
about 0.93 hours after the trigger and lasted for ~4 hours. A set
of 60s exposure images were obtained in the clear (roughly R)
filters. We detect the optical afterglow (Fu et al., GCN 39804;
Perez-Garcia et al al., GCN 39805; Brivio et al., GCN 39807;
Zhu et al., GCN 39809; Becerra et al., GCN 39810; Pérez-Fournon
et al., GCN 39812; Lee et al., GCN 39815; Ghosh et al., GCN 39816;
Han et al., GCN 39817; Jin et al., GCN 39822; Zhu et al., GCN 39827;
Gill et al., GCN 39831) with a mag of 18.7 +/- 0.2 (Vega) at 0.93
hours, it decayed to ~20.7 +/- 0.3 mag at ~5.4ks. The OT started
getting brighter slowly and reach a peak of ~19.5 +/- 0.2 mag
around 9.5ks, then decayed after that.