TITLE:   GCN CIRCULAR
NUMBER:  21048
SUBJECT: GRB 170428A: Xinglong 2.16-m upper limit and host galaxy candidate
DATE:    17/04/29 00:31:01 GMT
FROM:    Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>

D. Xu (NAOC), Y. Qin (Geneva Obs.), Y. Zhao, J.J. Jia, H.X. Feng, Z.P. 
Zhu (NAOC),  Y.D. Hu (IAA-CSIC), S. Feng, M.T. Ju (SHAO) report

We observed the field of short GRB 170428A (Beardmore et al., GCN 21042) 
using the 2.16-m telescope located at Xinglong, Hebei, China. We 
obtained 6x300s R-band frames, starting at 19:23:21 UT on 2017-04-28 
(i.e., 10.16 hr after the burst).

No optical source is detected at the XRT position (Beardmore & Evans, 
GCN 21047) in the stacked R-band image, down to a limiting magnitude of 
m(R)>21.0.

We note that in the SDSS and Pan-STARRS archival data there already 
exists a singe source within the XRT error circle, seemingly extended in 
the northeast - southwest direction. It is localised at

R.A (J2000) =   22:00:18.687
Dec. (J2000) = +26:54:56.51

with a brightness of m(r)~22.2 mag, and thus might be the host galaxy of 
this short burst.