TITLE:   GCN CIRCULAR
NUMBER:  39797
SUBJECT: GRB 250314A: Keck/NIRC2 J-band upper limit
DATE:    25/03/21 06:55:25 GMT
FROM:    Weikang Zheng at UC Berkeley <weikang@berkeley.edu>

WeiKang Zheng, Alexei V. Filippenko (UC Berkeley), Chris Fassnacht,

Prayaag Katta (UC Davis), D. B. Malesani (DAWN/NBI) and Jing Wang (NAOC),

report on behalf of the KAIT GRB team:


We observed the field of the SVOM GRB 250314A (Wang et al., GCN 39719)

with the NIRC2 camera on the Keck II 10 m telescope. The observations

were performed in the J band (without AO) starting on 2025 March 16 at

12:54:21 UTC (i.e., 2.0 days after the burst), and consisted of 2x120 s

exposures. At the reported NIR afterglow position (Malesani et al.,

GCN 39727; Malesani et al., GCN 39732), we do not detect any counterpart

with an upper limit of J > 19.4 mag (Vega).