[vsnet-grb-info 21307] GRB 181103A: Nanshan-1m optical upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23406
SUBJECT: GRB 181103A: Nanshan-1m optical upper limit
DATE:    18/11/04 11:51:29 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu at nao.cas.cn>

J.H. Liu (XAO), Z.P. Zhu, D. Xu (NAOC), X. Zhang, F.F. Song, Z.X. Li, 
J.Y. Bai, H.B. Niu, J.Z. Liu, A. Esamdin, L. Ma, Y. Zhang (XAO) report:

We observed the field of GRB 181103A (Tohuvavohu et al., GCN 23402) 
using the Nanshan-1m telescope located at Nanshan, Xinjiang, China. We 
optained 5¡Á300s, 1¡Á400s, 1¡Á600s R-band frames, starting at 23:07:05 UT 
on 2018-11-03, i.e, 18.73 hr after the Swift trigger.

No optical source was detected in the stacked image at the XRT position 
(Evans et al, GCN 23403), down to a limiting magnitude of R ~ 21.3 mag 
at the median time of 19.31hr post-burst, calibrated with the nearby 
SDSS field.