{
  "bibcode": "2016GCN.19150....1B",
  "body": "J. Bolmer, J. Greiner (both MPE Garching) and D.A. Kann (TLS Tautenburg) report on\nbehalf of the GROND team:\n\nWe re-observed the field of GRB 160303A (Swift trigger 677495; Beardmore et\nal., GCN #19126) simultaneously in g'r'i'z'JHK with GROND (Greiner et al.\n2008, PASP 120, 405) mounted at the 2.2m MPG telescope at the ESO La Silla\nObservatory (Chile).\n\nObservations started at 03:58 UT on 2016-03-05, 41.1h after the GRB\ntrigger. They were performed at an average seeing of 1.0\" and at an\naverage airmass of 1.6.\n\nWe still detect a faint source at the initially reported position (Graham et al. GCN#19144,\nde Ugarte Postigo et al. (GCN #19136)).\n\nBased on 96 min of exposure in g'r'i'z', at a mid-time\nof 04:52 UT, we derive the following preliminary magnitudes and upper\nlimits (in AB system):\n\ng' = 25.2 +/- 0.2 mag,\nr' = 25.1 +/- 0.2 mag,\ni' > 24.3 mag,\nz' > 24.4 mag,\n\nGiven detections and upper limits are calibrated against SDSS field stars. \nNo correction for the expected Galactic foreground extinction corresponding\nto a reddening of E_(B-V)=0.014 mag in the direction of the burst\n(Schlafly & Finkbeiner 2011) has been applied.\n\nCombining our GROND measurements with those from 10.63 h after the GRB\n(de Ugarte Postigo et al., GCN #19136), we obtain a decay slope of\nalpha = - 1.1 +/- 0.2 in the r' band.",
  "circularId": 19150,
  "createdOn": 1457188435000,
  "email": "jan@bolmer.de",
  "subject": "GRB160303A: further GROND observations",
  "submitter": "Jan Bolmer at MPE/Garching  <jan@bolmer.de>",
  "eventId": "GRB 160303A"
}