[vsnet-grb-info 13078] GRB130420A : Xinglong TNT optical upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  14415
SUBJECT: GRB130420A : Xinglong TNT optical upper limit
DATE:    13/04/20 15:59:58 GMT
FROM:    L.P. Xin at NAOC  <xlp at bao.ac.cn>

L.P. Xin, M. Zhai, J. Y. Wei, Y. L. Qiu,  J. Wang, 
J. S. Deng, C. Wu, X.H. Han  report on behalf of EAFON team:

We began to observe the field of GRB 130420A  (Page et al., GCN 14406 )
using  80cm TNT telescope located at Xinglong observatory, China
at 12:16:56 UT on 2013-04-20. We obtained 12x300s R-band images in a
poor seeing and cloudy weather, with a median time of 5.3 hr after the BAT trigger.

The afterglow reported (Page et a., GCN 14406 ) is not detected in the stacked image, 
down to a 3 sigma limit of R~18.0 mag, calibrated with USNO B2 stars.

This message may be cited.