[vsnet-grb-info 24761] GRB 200122A: Xinglong-2.16m optical upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  26860
SUBJECT: GRB 200122A: Xinglong-2.16m optical upper limit
DATE:    20/01/23 01:24:01 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu at nao.cas.cn>

X. Liu, D. Xu, H.J. Wang, Z.P. Zhu, B.Y. Yu (NAOC) report:

We observed the field of GRB 200122A (Sonbas et al., GCN 26844) using 
the Xinglong-2.16m telescope equipped with the BFOSC camera. 
Observations started at 22:14:52 UT on 2020-01-22 (i.e., 20.57 h after 
the BAT trigger), and 5x200 s R-band frames have been obtained.

No optical afterglow is detected at the Swift XRT's position in our 
stacked image, down to a limiting magnitude of m(R) ~ 22.0, calibrated 
with the nearby PanSTARRS field.