{
  "bibcode": "2014GCN.15789....1X",
  "body": "D. Xu (DARK/NBI), G.-J. Feng, J. Xu, A. Esamdin, L. Ma (XAO) report:\n\nWe observed the field of GRB 140206A (Lien et al., GCN 15784; Gotz et\nal., GCN 15785) using the 1m telescope located on Mt. Nanshan,\nXinjiang, China. Observations started at 12:30:16 UT on 2014-02-06\n(i.e., 5.216 hr after the burst), and a series of R-band frames were\nobtained.\n\nThe optical afterglow (Oksanen et al., GCN 15786; Oates & Lien, GCN\n15787) is clearly detected in each of our frames, and it decayed from\nM(R)=18.48+/-0.10 to m(R)=18.64+/-0.10 from 5.40 hr to 5.71 hr\npost-burst, calibrated with two nearby SDSS stars. Compared with the\nprevious measurements in GCNs 15786 & 15788, it shows that so far the\nafterglow has been decaying rather slowly and thus spectroscopy may be\ndoable even for a 2m class telescope in the coming hours.\n\nFurther observations are ongoing.",
  "circularId": 15789,
  "createdOn": 1391694907000,
  "email": "dong.dark@gmail.com",
  "subject": "GRB 140206A: Nanshan optical observations",
  "submitter": "Dong Xu at DARK/NBI  <dong.dark@gmail.com>",
  "eventId": "GRB 140206A"
}