{
  "bibcode": "2015GCN.18195....1K",
  "body": "T. Kruehler (ESO), F. Schrey, W. Bornemann, A. Rau and J. Greiner\n(all MPE)  report on behalf of a larger collaboration:\n\nWe observed the field of GRB 150821A (Swift trigger 652847;\nTroja et al., GCN 18186) simultaneously in g'r'i'z'JHK\nwith GROND (Greiner et al. 2008, PASP 120, 405) mounted\nat the 2.2 m MPG telescope at ESO La Silla Observatory (Chile).\n\nObservations started at 02:02 UT on 2015-08-22, 16.3 hours after the\nGRB trigger. For the optical afterglow (Troja et al., GCN 18186,\nD'Elia et al. GCN 18187, Kuin & Troja, GCN 18192) we derive magnitudes of:\n\ng = 23.2 +- 0.1\nr = 22.6 +- 0.1\ni = 22.3 +- 0.1\nz = 22.0 +- 0.2\n\nat a midtime of 17.0 hours after the trigger. This photometry is in the\nAB system and calibrated against GROND zeropoints. Because GROND is \npresently being recommissioned, our measurements are preliminary.",
  "circularId": 18195,
  "createdOn": 1440216688000,
  "email": "kruehler@mpe.mpg.de",
  "subject": "GRB 150821A: GROND afterglow observations",
  "submitter": "Thomas Kruehler at MPE Garching  <kruehler@mpe.mpg.de>",
  "eventId": "GRB 150821A"
}