{
  "bibcode": "2013GCN.14488....1H",
  "body": "Veli-Pekka Hentunen, Markku Nissinen and Tuomo Salmi (Taurus Hill\nObservatory, Varkaus, Finland) report:\n\nWe have continued observing GRB 130427A optical afterglow at iTelescope\nobservatory T21 (Mayhill, New Mexico) 0.43-m/6.8 astrograph and\nFLI-PL6303E CCD. Two unfiltered, two photometric R filter and two\nphotometric V filter images with 600 sec exposure time were made.\n\nThe following magnitudes were obtained from the observations using\nNOMAD1 1176-0248446 (R=13.520, V=13.120) as the comparison:\n\nTmid(h)+T0      Filter     Exp. time         Mag          Mag err. \n22.67              V              600                17.73V         0.11\n22.85              V              600                17.72V         0.11\n23.10              unfiltered   600                18.01CR       0.07\n23.27              unfiltered   600                18.22CR       0.09\n23.56              R              600                18.18R          0.12\n23.74              R              600                18.36R          0.14",
  "circularId": 14488,
  "createdOn": 1367149066000,
  "email": "veli-pekka.hentunen@kassiopeia.net",
  "subject": "GRB 130427A: Continued iTelescope T21 optical observations",
  "submitter": "Veli-Pekka Hentunen at Taurus Hill Obs,A95  <veli-pekka.hentunen@kassiopeia.net>",
  "eventId": "GRB 130427A"
}