TITLE:   GCN CIRCULAR
NUMBER:  28701
SUBJECT: GRB 201020A: Nanshan/NEXT optical observations
DATE:    20/10/20 16:08:23 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

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

We observed the field of GRB 201020A (Ambrosi et al., GCN 28696) using 
the NEXT-0.6m telescope located at Nanshan, Xinjiang, China. We obtained 
15x120s frames in the Sloan r-band, starting at 13:48:25 UT on 
2020-10-20, i.e., 8.02 hr after the BAT trigger.

The optical afterglow (Ambrosi et al., GCN 28696; Adachi et al., GCN 
28697) of the burst is clearly detected in our stacked image, with r = 
19.69 +/- 0.06 mag at T_mid = 0.3461 day post-burst, calibrated with 
nearby PS1 stars.