[vsnet-grb-info 27455] GRB 210222B: KAIT Optical Upper Limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  29558
SUBJECT: GRB 210222B: KAIT Optical Upper Limit
DATE:    21/02/23 16:48:01 GMT
FROM:    Weikang Zheng at UC Berkeley  <weikang at 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 Swift GRB 210222B (Gropp et al.,

GCN 29545) starting at ~0.44 days after the burst. A total of

30x60s images were obtained in the clear (roughly R) filters.

We do not detect the optical afterglow (Gropp et al., GCN 29545;

Hu et al., GCNC 29546; Strausbaugh et al., GCNC 29547; Mong et al.,

GCNC 29548; Perley, GCNC 29549; Agui Fernandez et al., GCNC 29552;

Lipunov et al., GCNC 29554; Jelinek et al., GCN 29557) in the

co-add images, down to a limiting magnitude of ~20.0 mag calibrated

to the USNOB1.0 catalog.