[vsnet-grb-info 20487] GRB 180402A: KAIT Optical Upper Limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22583
SUBJECT: GRB 180402A: KAIT Optical Upper Limit
DATE:    18/04/02 17:40:39 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 180402A (Lien et al.,
GCN 22580 starting at 09:47:14 UT, 135 s after the burst.
Observations were performed with an automatic sequence in the
clear (roughly R), V, and I filters, and the exposure time was 20 s
per image. We do not detect any optical afterglow candidate within
the XRT position error circle (Lien et al., GCN 22580).
The typical limiting magnitude of our single clear image is about
18.5 mag calibrated to the APASS catalog.