GCN Circular 22145
Subject
GRB 171120A: Xinglong-2.16m optical upper limit
Date
2017-11-22T04:24:59Z (6 years ago)
From
Dong Xu at NAOC/CAS <dxu@nao.cas.cn>
Z.P. Zhu, H.X. Feng, D. Xu (NAOC), Y. Zhao, F. Xiao (NAOC), S.B. Qian
(YNAO), Y.D. Hu (IAA-CSIC) report
We observed the field of GRB 171120A (Tohuvavohu et al., GCN 22133)
using the 2.16-m telescope located at Xinglong, Hebei, China, equipped
with BFOSC. We obtained 1x600s and 2x900s R-band frames, starting at
18:54:02 UT on 2017-11-20, i.e., 5.57 hr after the BAT trigger.
No optical source was detected in the stacked image at the XRT position
(Evens et al., GCN 22135), down to the limiting magnitude of R~21.5 mag
at the median time of 5.95 hr post-burst, calibrated with the SDSS field.