GCN Circular 31998
Subject
GRB 220430A: Nanshan/HMT optical upper limit
Date
2022-05-06T04:52:43Z (2 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
S.Q. Jiang (NAOC), Z.P. Zhu (NAOC,HUST), S.Y. Fu, X. Liu, D. Xu (NAOC),
X. Gao
(Urumqi No.1 Senior High School), J.Z. Liu (XAO) report:
We observed the field of GRB 220430A detected by Swift (Ambrosi et al.,
GCN 31972) and AGILE (Ursi et al., GCN 31975) using the HMT-0.5m
telescope located at Nanshan, Xinjiang, China. Observations started at
13:58:51 UT on 2022-04-30 (i.e., 5.6 min after the BAT trigger), and
3x20, 3x40, 4x60, 12x90 s unfiltered frames were obtained.
No optical source is detected in our stacked image at the XRT position
(Osborne et al., GCN 31973), down to a limiting magnitude of ~19.2,
calibrated with the Gaia DR2 stars.