TITLE:   GCN CIRCULAR
NUMBER:  30679
SUBJECT: GRB 210822A: KAIT Optical Afterglow Confirmation
DATE:    21/08/22 15:25:27 GMT
FROM:    Weikang Zheng at UC Berkeley  <weikang@berkeley.edu>

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, responded to the Swift GRB 210822A (Page et al.,

GCN 30677; see also GECAM detection, Wang et al., GCN 30678)

starting at 09:20:02 UT, 104s after the burst.

Observations were performed with a sequence in the clear (roughly R),

V, and I filters, and the exposure time was 20 s per image.

The bright optical afterglow reported by UVOT (Page et al., GCN 30677)

was clearly detected in our single image. We measure its brightness

of 11.4 mag in our first clear image at 114s after the burst, then

decayed to 16.1 mag at 2690s after the burst.

A preliminary KAIT clear band light curve is available at:


https://w.astro.berkeley.edu/~zwk/grb/GRB210822A/GRB210822A_kait.png