TITLE:   GCN CIRCULAR
NUMBER:  34498
SUBJECT: GRB 230818A: Nickel and KAIT telescope optical observations
DATE:    23/08/19 22:13:43 GMT
FROM:    Weikang Zheng at UC Berkeley <weikang@berkeley.edu>

Neil Pichay, Elma Chuang, WeiKang Zheng and Alex Filippenko (UC Berkeley)

report on behalf of the KAIT GRB team:


We observed the field of GRB 230818A (Fermi GBM team, GCN 34478;

Tohuvavohu et al., GCN 34479) with the 1-m Nickel and 0.76-m KAIT

telescopes located at Lick observatory, California. Observations

started about 0.21 days after the burst. A total of 6 images (600s

exposure each) in R band were taken with Nickel telescopes, while

KAIT images were taken in clear band, with 60s exposure and coadded.

We detected the optical afterglow (Lipunov et al., GCNs 34476, 34477,

34481, 34482; Gompertz et al., GCN 34480; Moskvitin et al., GCN 34483;

Malesani et al., GCN 34485; Siegel and Tohuvavohu, GCN 34486; Pankov

et al., GCN 34487; Quadri and Strabla, GCN 34488; Klose et al., GCN

34491; Moskvitin et al., GCN 34495; 34497) and measure the following

magnitude calibrated to the Pan-STARRS1 catalog:



t-t0(days) filter mag   err

0.218      clear  21.8  0.3

0.226      R      21.6  0.2

0.324      clear  21.3  0.3