TITLE:   GCN CIRCULAR
NUMBER:  28549
SUBJECT: GRB 201001A: Xinglong-2.16m optical upper limit
DATE:    20/10/02 13:15:29 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

S.Y. Fu, Z.P. Zhu, X. Liu, D. Xu (NAOC) report:

We observed the field of GRB 201001A (Simpson et al., GCN 28539) using 
the Xinglong-2.16m telescope equipped with the BFOSC camera. 
Observations were carried out starting at 19:29:17 UT on 2020-10-01 
(i.e., about 9.5 hr after the BAT trigger), and 10x180s, 9x360s R-band 
frames were obtained.

No optical source is detected in our stacked image at the enhanced XRT 
position (Evans et al., GCN 28540), down to a upper limit of R~21.0, 
calibrated with the nearby PanSTARRS field.

We acknowledge great support from the Xinglong-2.16m observing staff, in 
particular J. Zheng and A.Y. Zhou.