[vsnet-grb-info 27298] GRB 210205A: Nanshan/NEXT optical upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  29401
SUBJECT: GRB 210205A: Nanshan/NEXT optical upper limit
DATE:    21/02/05 16:20:03 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu at nao.cas.cn>

S.Y. Fu (NAOC), Z.P. Zhu (HUST,NAOC), X. Liu, D. Xu (NAOC), X. Gao 
(Urumqi No.1 Senior High School), J.Z. Liu (XAO) report:

We observed the field of GRB 210205A (Dichiara et al., GCN 29397) using 
the NEXT-0.6m telescope located at Nanshan, Xinjiang, China. We obtained 
3x40 s, 4x60 s, 12x90 s frames in the Sloan r-band, starting at 12:09:46 
UT on 2021-02-05, i.e., 58.5 min after the BAT trigger.

No optical source is detected in our stacked image at the enhanced XRT 
position (Osborne et al., GCN 29399), down to a limiting magnitude of 
r~19.9, calibrated with the nearby PanSTARRS field.