GCN Circular 41873
Subject
GRB 250916A: KAIT optical observations
Event
Date
2025-09-18T22:13:06Z (4 days ago)
From
Weikang Zheng at UC Berkeley <weikang@berkeley.edu>
Via
email
WeiKang Zheng (UCB) 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 GRB 250916A (Fermi GBM
team, GCN 41839; Arya et al., GCN 41843; Cheung et al., GCN 41855;
Waratkar et al., GCN 41871) starting at ~0.783d and again at ~1.738d
after the burst. A set of clear (roughly R) filter images were
obtained. We clearly detected the optical afterglow (Belkin et al.,
GCN 41847; Mohan et al., GCN 41858; Moskvitin et al., GCN 41859;
Burkhonov et al., GCN 41860; de Ugarte Postigo et al., GCN 41863;
Moskvitin et al., GCN 41870) in our coadd images. We estimate the
afterglow to be 19.35 +/- 0.1 and 20.10 +/- 0.1 mag (Vega) at a mid
time of ~0.824d and ~1.807d respectively.