GCN Circular 29530
Subject
GRB 210218A: NEXT optical upper limit
Date
2021-02-18T14:28:05Z (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 210218A (Sbarufatti et al., GCN 29529)
using the NEXT-0.6m optical telescope located at Nanshan, Xinjiang,
China. Observations automatically started at 13:36:52 UT on 2021-02-18,
i.e., 93 s after the BAT trigger. We obtained 3x40 s, 4x60 s and 12x90 s
frames in the Sloan r-filter.
No credible optical transient is detected in our stacked image within
the Swift/BAT error circle, down to a limiting magnitude of r ~ 20.4,
calibrated with the nearby PanSTARRS field.