{
  "bibcode": "2015GCN.17821....1Y",
  "body": "R. Yates, F. Knust (both MPE Garching), D. A. Kann (TLS Tautenburg), and\nJ. Greiner (MPE Garching) report on behalf of the GROND team:\n\nWe observed the field of GRB 150514A (Fermi trigger 453321308; LAT\ndetection: Kocevski et al., GCN # 17816; GBM detection: Roberts et al.,\nGCN # 17819) simultaneously in g'r'i'z'JHK with GROND (Greiner et al.\n2008, PASP 120, 405) mounted at the 2.2 m MPG telescope at ESO La Silla\nObservatory (Chile).\n\nObservations started at 23:36 UT on 2015-05-15, 29.0 hrs after the GRB\ntrigger. They were performed at an average seeing of 1\".5 and at an\naverage airmass of 2.1.\n\nCoincident with the UVOT source reported by Marshall & Cannizzo (GCN #\n17820), we detect a bright source.\n\nBased on 7.7 min of total exposure time in g'r'i'z' and 8 min in JHK\ncentered 29.15 hrs after the GRB, we estimate the following preliminary\nmagnitudes (all in the AB system):\n\ng' = 20.5 +/- 0.1 mag,\nr' = 20.1 +/- 0.1 mag,\ni' = 19.9 +/- 0.1 mag,\nz' = 19.6 +/- 0.1 mag,\nJ = 19.2 +/- 0.2 mag, and\nH = 18.6 +/- 0.2 mag.\n\nCompared with the UVOT detections reported by Marshall & Cannizzo (GCN #\n17820; 18th magnitude), the source has clearly faded, establishing it as\nthe afterglow of GRB 150514A.\n\nWe note that similar to other LAT-detected GRBs, this is a very bright\nafterglow. Spectral follow-up is encouraged.\n\nGiven magnitudes are calibrated against GROND zero points (g'r'i'z') as\nwell as 2MASS field stars (JHK) and are not corrected for the expected\nGalactic foreground extinction corresponding to a reddening of E_(B-V) =\n0.02 mag in the direction of the burst (Schlegel et al. 1998).",
  "circularId": 17821,
  "createdOn": 1431736529000,
  "email": "kann@tls-tautenburg.de",
  "subject": "GRB 150514A: GROND Bright Afterglow Confirmation",
  "submitter": "Alexander Kann at TLS Tautenburg  <kann@tls-tautenburg.de>",
  "eventId": "GRB 150514A"
}