[vsnet-grb-info 23425] GRB 190828B: Dabancheng-0.5m optical upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  25524
SUBJECT: GRB 190828B: Dabancheng-0.5m optical upper limit
DATE:    19/08/28 16:31:06 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu at nao.cas.cn>

B.Y. Yu, X. Liu, D. Xu, Z.P. Zhu (NAOC), J.H. Liu (XAO), X. Gao (Urumqi 
No.1 Senior High School), Z.B. Zhang (XJTS) report:

We observed the field of GRB 190828B (Dichiara et al., GCN 25517) using 
the Half-Meter Telescope (HMT-0.5m) located at Dabancheng, Xinjiang, 
China. We obtained 5x60 s unfiltered frames, started at 13:56:32 UT on 
2019-08-28, i.e., 56.5 min after the burst.

No optical source is detected at the XRT position (Dichiara et al., 
GCN25517) in our stacked image, down to a limiting magnitude of R~17.8, 
calibrated with the nearby SDSS field.