GCN Circular 29250
Subject
GRB 210104B: Nanshan/NEXT optical upper limit
Date
2021-01-05T00:33:27Z (3 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
S.Y. Fu (NAOC), Z.P. Zhu (NAOC, HUST), X. Liu, D. Xu (NAOC), X. Gao
(Urumqi No.1 Senior High School), J.Z. Liu (XAO) report:
We observed the field of GRB 210104B (Laha et al., GCN 29243) using the
NEXT-0.6m optical telescope located at Nanshan, Xinjiang, China.
Observations automatically started at UT on 2020-12-21, i.e., 75 s
after the BAT trigger. We obtained a series of 40 s, 60 s and 90 s
frames in the Sloan r-filter.
No optical source is detected in our stacked image at the Swift/XRT
position (Laha et al., GCN 29243), down to a limiting magnitude of
r~21.0, calibrated with the nearby PanSTARRS field.