GCN Circular 29551
Subject
GRB 210222B: NEXT early optical afterglow observations
Date
2021-02-23T05:05:58Z (3 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
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 210222B (Gropp et al., GCN 29545) using the
NEXT-0.6m optical telescope located at Nanshan, Xinjiang, China.
Observations automatically started at 22:39:01 UT on 2021-02-22, i.e.,
95 s after the BAT trigger. We obtained a series of 40 s and 60 s frames
during the local morning twilight in the Sloan r-filter.
The previously reported optical afterglow (Gropp et al., GCN 29545; Hu
et al., GCN 29546; Strausbaugh et al., GCN 29547; Mong et al., GCN
29548, 29550; Perley et al., GCN 29549) is detected in the stacked
images of the first three exposures, with r = 14.5 +/- 0.3 mag,
calibrated with nearby PS1 stars.