{
  "bibcode": "2016GCN.19396....1K",
  "body": "F. Knust, C. Delvaux, J. Greiner (all MPE Garching) report on behalf of\nthe GROND team:\n\nWe observed the field of GRB 160506A (Swift trigger 685245; Hagen et al.,\nGCN #19394) 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  06:45 UT on 2016-05-06, 3.25 hrs after the GRB\ntrigger. They were performed through substantial cirrus at an average\nseeing of 2.1\" and at an average airmass of 1.1.\n\nWe do not detect any source within the Swift-XRT error circle reported by\nOsborne et al. (GCN #19395) down to\n\ng' > 20.9 mag,\nr' > 22.1 mag,\ni' > 21.5 mag,\nz' > 21.7 mag,\nJ > 19.4 mag,\nH > 19.1 mag, and\nK > 17.2 mag.\n(all in AB),\n\nbut we see two faint sources north-east and sout-west of the XRT error\ncircle, each about 4 arcsec away from the XRT centroid.\n\nGiven magnitudes are calibrated against USNO as well as 2MASS field stars\nand are not corrected for the expected Galactic foreground extinction\ncorresponding to a reddening of E_(B-V)=0.26 mag in the direction of the\nburst (Schlegel et al. 1998).",
  "circularId": 19396,
  "createdOn": 1462525972000,
  "email": "fknust@mpe.mpg.de",
  "subject": "GRB 160506A: GROND upper limits",
  "submitter": "Fabian Knust at MPE/GROND  <fknust@mpe.mpg.de>",
  "eventId": "GRB 160506A"
}