GCN Circular 40116
Subject
GRB 250407A: KAIT Optical Afterglow Candidate
Event
Date
2025-04-08T05:41:09Z (8 months ago)
From
Weikang Zheng at UC Berkeley <weikang@berkeley.edu>
Via
email
WeiKang Zheng and Alexei V. Filippenko (UC Berkeley) 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 250407A (GBM team,
GCN 40104; Preis et al., GCN 40105; Mukherjee et al., GCN 40114)
around the X-ray afterglow location (Molkov et al., GCN 40110;
Dichiara et al., GCN 40113) starting at 04:17, Apr. 08 UT, about
12.48 hours after the burst. A set of clear (roughly R) filter
images were obtained. Within the XRT afterglow (Dichiara et al.,
GCN 40113) error circle, we detected an uncataloged optical
afterglow candidate at J2000 position of (error ~0.5"):
RA: 07:23:02.11
Dec: +36:47:54.97
We estimate the clear band magnitude to be ~20.1 +/- 0.3 mag (Vega)
at 12.48 hours after the burst. Further observations are encouraged.