{
  "bibcode": "2015GCN.17767....1K",
  "body": "F. Knust (MPE Garching), D. A. Kann (TLS Tautenburg), T. Kruehler (ESO),\nand J. Greiner (MPE Garching) report on behalf of the GROND team:\n\nWe observed the field of GRB 150428A (Swift trigger 639275; Page et al.,\nGCN #17765) 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 02:24 UT on 2015-04-28, 53 minutes after the GRB\ntrigger, following a delay due to the labeling of the event as \"not a GRB\"\nin the BACODINEs. They were performed at an average seeing of 0\".9 and at\nan average airmass of 1.2.\n\nWe detect a source at (J2000):\n\nRA =    12:34:09.26\nDec. = +06:57:08.7\n\nwith an error of 0\".5 in each coordinate.\n\nBased on 25 min of total exposure time in g'r'i'z' centered 1.41 hrs after\nthe GRB, we estimate the following preliminary magnitudes (all in AB\nsystem):\n\ng' = 24.1 +/- 0.4 mag,\nr' = 23.0 +/- 0.1 mag,\ni' = 22.7 +/- 0.1 mag, and\nz' = 23.2 +/- 0.2 mag.\n\nAt this time, we cannot establish fading. At this position, we also detect\na source in the SDSS, which implies that this would be the host galaxy of\nthis GRB. We note the hydrogen column density as derived from X-rays\n(Page et al., GCN #17765) is much higher than the (very low) Galactic NH,\nimplying this may be an optically dust-suppressed event.\n\nGiven magnitudes are calibrated against SDSS field stars and are not\ncorrected for the expected Galactic foreground extinction corresponding to\na reddening of E_(B-V)=0.02 mag in the direction of the burst (Schlegel et\nal. 1998).",
  "circularId": 17767,
  "createdOn": 1430194554000,
  "email": "kann@tls-tautenburg.de",
  "subject": "GRB 150428A: GROND Dark Burst Host Candidate",
  "submitter": "Alexander Kann at TLS Tautenburg  <kann@tls-tautenburg.de>",
  "eventId": "GRB 150428A"
}