[vsnet-grb-info 21182] GRB 180930A: KAIT Optical Upper Limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23281
SUBJECT: GRB 180930A: KAIT Optical Upper Limit
DATE:    18/09/30 18:07:48 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 180930A (Tohuvavohu et al.,
GCN 23279) starting at 12:45:41 UT, 112 seconds after the burst
under dawn twilight condition. 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 enhanced XRT position error
circle (Evans et al., GCN 23280) neither in single image, nor in
the co-add images. The typical limiting magnitude of our single
clear image is about 18.5 mag calibrated to the Pan-STARRS1 catalog.