{
  "bibcode": "2017GCN.22274....1Z",
  "body": "X. Zhang, P. Zong, J.H. Liu (XAO), H.X. Feng, Z.P. Zhu, D. Xu (NAOC), \nH.B. Niu, J.Z. Liu, A. Esamdin, L. Ma, Y. Zhang (XAO) report on behalf \nof a larger collaboration:\n\nWe observed the field of GRB 171222A (Racusin et al., GCN 22265) using \nthe 1m telescope located at Nanshan, Xinjiang, China. We obtained 6x300s \nR-band frames, starting at 18:14:36 UT on 2017-12-22, i.e., 1.83 hr \nafter the BAT trigger.\n\nAn uncatalogued and fading optical transient (OT) is detected at the XRT \nposition (Osborne et al., GCN 22266) as well as the NOT position (Perley \net al., GCN 22269) in our images. Preliminary photometry results are as \nfollows:\n\nTmid-T0 Exposure  Filter    Mag(R)    MagErr(R)\n(hr)           (s)\n1.87        1x300       R        20.86        0.21\n2.68        3x300       R        21.47        0.22\n7.87        2x300       R        21.72        0.22\n\nPhotometry is calibrated with nearby USNO-B1.0 stars (R2 magnitudes), \nand errors are only statistical values. We thus conclude that this OT is \nthe optical afterglow of GRB 171222A.",
  "circularId": 22274,
  "createdOn": 1514037659000,
  "email": "dxu@nao.cas.cn",
  "subject": "GRB 171222A: Nanshan-1m optical afterglow detection",
  "submitter": "Dong Xu at NAOC/CAS  <dxu@nao.cas.cn>",
  "eventId": "GRB 171222A"
}