{
  "bibcode": "2018GCN.23532....1H",
  "body": "X. H. Han, R. S. Zhang,  L. P. Xin,  J. Wang,  P. P. Zhang, J. Y. Wei,   E. W. Liang, \nX. G. Wang, Y. J. Xiao,   Y. G. Yang,  X. M. Lu,  L. Huang,    H. B. Cai,   \nX. M. Meng,   Y. L. Qiu,  Y. Xu, Y.  J. Xiao, Y. T. Zheng,  C. Wu,   \nJ. S. Deng, D. W. Xu,  D. TURPIN, H. L. Li, and W. L. Dong, report:\n\nWe  observed  GRB 181213A  ( Evans et al., GCN 23525; Osborne \net al., GCN 23528 )  with  GWAC-F60A 60cm optical telescope \nat 21:21:34 UT, Dec. 13th 2018,  about 8.4  hours after the burst. \nThe exposure time is 150 sec in R band. the airmass is 1.56. \n\nThe optical afterglow reported by (Lipunov et al., GCN 23526; Hu et al. GCN 23527; \n Siegel  et al., GCN 23529; Belkin et al., GCN 23530) is not detected with an upper \nlimit of 18.2 mag in R band image. The brightness is calibrated by nearby USNO-B1.0 stars.\n\nGWAC-F60A is operated by Guangxi university and NAOC, CAS, \nat Xinglong observatory, China.\n\nThe message may be cited.",
  "circularId": 23532,
  "createdOn": 1544752095000,
  "email": "xlp@nao.cas.cn",
  "subject": "GRB 181213A: GWAC-F60A upper limit",
  "submitter": "L.P. Xin at NAOC  <xlp@nao.cas.cn>",
  "eventId": "GRB 181213A"
}