TITLE:   GCN CIRCULAR
NUMBER:  41251
SUBJECT: GRB 250806A: KAIT optical upper limit
DATE:    25/08/06 17:32:12 GMT
FROM:    Weikang Zheng at UC Berkeley <weikang@berkeley.edu>

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 SVOM GRB 250806A (Xie

et al., GCN 41243) starting at 08:00:40, Aug. 06 UT, 146 seconds

after the burst. Observations were performed in 3 x 3 tiling mode,

and a set of clear (roughly R) filter images were obtained.

Preliminary analysis do not reveal any new optical counterpart

candidate within the Swift/XRT error circles (Campana et al., GCN

41249), neither in single image, nor in the co-add images. Our

typical limiting magnitude of single image is about ~19.5 mag,

with the first image covered Swift/XRT position at 237s after the

burst.  Our result is consistent with the upper limit reported by

other groups (Wu et al., GCN 41244; Fortin et al., GCN 41245;

Freeberg et al., GCN 41247; Xin et al., GCN 41250).