[vsnet-grb-info 18018] GRB 160525B: Nanshan optical upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  19466
SUBJECT: GRB 160525B: Nanshan optical upper limit
DATE:    16/05/25 21:32:53 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu at nao.cas.cn>

D. Xu, Y.-H. Han (both NAOC/CAS), S.-G. Ma, A. Esamdin, J.-Z. Liu, L. Ma 
(all XAO) report:

We observed the field of GRB 160525B (Krimm et al., GCN 19459) using the 
1m telescope located at Nanshan, Xinjiang, China. We obtained 5x300s 
R-band frames, starting at 15:26:24 UT on 2016-05-25, i.e., 6.02 hr 
after the burst.

No optical source is detected at the XRT position (Beardmore et al., GCN 
19463) in the stacked image, down to a limiting magnitude of m(R)>21.5, 
calibrated with the nearby SDSS field.