TITLE: GCN CIRCULAR NUMBER: 14623 SUBJECT: GRB 130511A: Upper limit by Xinglong TNT optical observation DATE: 13/05/11 15:14:12 GMT FROM: L.P. Xin at NAOC 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 130511A (Krimm et al. GCN 14620) using 80cm TNT telescope located at Xinglong observatory, China, at 41.9 min after the burst on 12:12:41 UT, May 11th, 2013. 15*300sec R-band images was obtained. The reported optical counterpart (Krimm et al. GCN 14620; Cucchiara et a. GCN 14621) was not detected in all single images and the combined image, down to the upper limit of R~19.6 mag calibrated by USNO B1.0 R2 mag, at the mean time of 62.3 min after the trigger time. This message may be cited.