{
  "bibcode": "2018GCN.22479....1B",
  "body": "J. Bolmer (ESO/MPE) reports:\n\nI observed the field of GRB 180314A (Swift trigger 814129; P. D'Avanzo et al.,\nGCN 22478) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008,\nPASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla\nObservatory (Chile).\n\nObservations started at 00:47 UT on March 14, 2018, 4 minutes after\nthe GRB trigger. They were performed at an average seeing of 1\".1 and at\nan average airmass of 1.03.\n\nWe clearly detect the NIR/optical transient of GRB 180314A at\nthe position reported by P. D'Avanzo et al. (GCN 22478).\nBased on total exposure of 200 seconds in g���r���i'z' at a midtime\nof 00:50 UT, 7 minutes after the burst, we measure\nthe following preliminary magnitudes (AB magnitude\nsystem):\n\ng' = 17.87 +/- 0.01 mag,\nr' = 17.57 +/- 0.02 mag,\ni' = 17.36 +/- 0.03 mag,\nz' = 17.25 +/- 0.03 mag\n\nMagnitudes are calibrated against PanSTARRS field stars and are not\ncorrected for the Galactic foreground extinction corresponding to a\nreddening of E_(B-V)= 0.07 mag in the direction of the burst (Schlegel et al. 1998).\n\nObservations are continuing.",
  "circularId": 22479,
  "createdOn": 1520990239000,
  "email": "jan@bolmer.de",
  "subject": "GRB180314A: GROND detection of the afterglow",
  "submitter": "Jan Bolmer at MPE/Garching  <jan@bolmer.de>",
  "eventId": "GRB 180314A"
}