[vsnet-grb-info 16554] GRB 150518A : Xinglong TNT upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17835
SUBJECT: GRB 150518A : Xinglong TNT upper limit
DATE:    15/05/21 04:01:03 GMT
FROM:    L.P. Xin at NAOC  <xlp at bao.ac.cn>

L. P. Xin,   X. F. Wang,  J. Y. Wei,  Y. L. Qiu,  J. S. Deng,
J. Wang,  X. H. Han and C. Wu on behalf of EAFON report:
 
We  observed GRB 150518A (Kawamuro, et al., GCN 17825)
with Xinglong  0.8-m TNT telescope during 2015-05-20, 
16:51:46 and 18:16:34 (UT), bout 43.2-44.7 hour after the trigger time.
 
No any source was detected in our 17*300sec R-band coadded image within 
the Swift-XRT error circle (Sbarufattim et al., GCN 17827) and at the 
location of the reported source (Xu et al., GCN 17829; Mao et al., GCN 17830) 
down to the 3 sigma limit of 20.7 mag, calibrated by USNO B1.0 R2 mag.