{
  "bibcode": "2013GCN.14968....1G",
  "body": "C. Guidorzi (Ferrara U.), C.G. Mundell, I.A. Steele (LJMU),\non behalf of a large collaboration report:\n\nOn 2013 July 03 (09:03:30 UT) we began observing the field of the\npossible optical afterglow of Fermi394416326 (Singer GCN Circ. 14967)\nwith the 2-m Faulkes Telescope North in Hawaii.\nObservations were carried out using the BVRi filters.\nWe clearly detect the optical counterpart discovered by\nSinger et al. with the following magnitudes\n\nTime from GRB   Filter  Exposure[s]    Magnitude\n(days)\n----------------------------------------------------\n1.38            i'      100            18.61 +- 0.07\n1.38            R       120            18.46 +- 0.05\n----------------------------------------------------\n\nThe calibration was performed using the i' magnitudes of\nSDSS catalogue field stars and the R magnitudes obtained\nusing the transformations by Jordi et al (2006).",
  "circularId": 14968,
  "createdOn": 1372845752000,
  "email": "guidorzi@fe.infn.it",
  "subject": "Fermi394416326: FTN detection",
  "submitter": "Cristiano Guidorzi at Ferrara U,Italy  <guidorzi@fe.infn.it>"
}