{
  "bibcode": "2013GCN.14158....1V",
  "body": "F.J. Virgili (LJMU), C. Guidorzi (U. Ferrara), and A. Melandri \n(INAF-OAB) report:\n\n\"The 2-m Faulkes Telescope North robotically followed up GRB 130131A\n(Swift trigger 547407, Grupe et al. GCN 14156) 2.88 min after the GRB \ntrigger time. No optical counterpart is detected\nwithin the XRT error circle to the following conservative limits:\n\nMidtime from GRB    Exposure    Filter    Magnitude\n       (min)                        (s)\n-------------------------------------------------\n       3.4                       3x10s         R        >19.2\n       28.9                      720s          R        >20.6\n       33.7                      700s          i'        >20.1\n-------------------------------------------------\n\nMagnitudes are calibrated with nearby USNOB-1 and SDSS stars.\"",
  "circularId": 14158,
  "createdOn": 1359649673000,
  "email": "fjv@astro.livjm.ac.uk",
  "subject": "GRB 130131A - Faulkes Telescope North Observations",
  "submitter": "Francisco Virgili at Liverpool John Moores U  <fjv@astro.livjm.ac.uk>",
  "eventId": "GRB 130131A"
}