TITLE:   GCN CIRCULAR
NUMBER:  14571
SUBJECT: GRB 130505A:  Xinglong TNT optical observations
DATE:    13/05/05 14:32:29 GMT
FROM:    L.P. Xin at NAOC  <xlp@bao.ac.cn>

L. P. Xin, 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 130505A  (Cannizzo, et al., GCN 14563)
using  80cm TNT telescope located at Xinglong observatory, China
at 12:25:39 UT on 2013-05-05.  We obtained several R-band images.  

The reported optical counterpart (Cannizzo, et al., GCN 14563) is detected in all images. 
A prelinary analysis shows that its brightness is decaying from R~18.05 to R~18.68 mag
during  4.05h and 4.85h after the trigger time. 
These magnitudes are calibrated with USNO B1.0 R2 stars, 

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