TITLE: GCN CIRCULAR NUMBER: 6908 SUBJECT: GRB 20071013: Xinglong TNT optical Upper Limit DATE: 07/10/13 14:11:24 GMT FROM: L.P. Xin at NAOC L.P. Xin, M. Zhai, Y.L. Qiu, J.Y. Wei, J.Y. Hu, J.S. Deng, J.Wang and W.K. Zheng on behalf of EAFON report: We have imaged the field of GRB 071013(Marshall et al., GCN 6907) with the TNT 0.8m telescope at Xinglong Observatory started from 12:14:08 UT , 289s after the burst. A series of White and R band images were obtained, no new source was found in our combined images within the error region of the BAT. The 3-sigma limit derived form USNO-B1.0 R mag is ------------------------------------ Band Mid time Exp time Limit Mag White 504s 19*20s 20.0 R 1538s 20*60s 20.2 Further observation is under going. This message may be cited.