{
  "bibcode": "2010GCN.11013....1O",
  "body": "F. Olivares, R. Filgas and J. Greiner (all MPE Garching) report on behalf of\nthe GROND team:\n\nWe observed the field of GRB 100728B (Swift trigger 430172; Morris et al.,\nGCN #11009) simultaneously in JHK with GROND (Greiner et al. 2008, PASP\n120, 405) mounted at the 2.2 m MPI/ESO telescope at La Silla Observatory\n(Chile).\n\nObservations started at 10:34 UT, 2 minutes after the GRB trigger. They\nwere performed during astronomical twilight at an average airmass of 1.2.\n\nWe detect a single point source at position reported by Perley et al. (GCN\n#11007), Morris et al. (GCN #11009), Ivarsen et al. (GCN #11011) and\nElenin et al. (GCN #11012).\n\nBased on the first 4 min of total exposures in JHK, we estimate\npreliminary magnitudes (all in AB system) of\n\nJ = 16.4 +- 0.1 mag,\n\nH = 16.2 +- 0.1 mag and\n\nK = 16.0 +- 0.1 mag\n\nGiven magnitudes are calibrated against 2MASS field stars and are not\ncorrected for the expected Galactic foreground extinction corresponding to\na reddening of E_(B-V)=0.07 mag in the direction of the burst (Schlegel et\nal. 1998).",
  "circularId": 11013,
  "createdOn": 1280323687000,
  "email": "filgas@mpe.mpg.de",
  "subject": "GRB 100728B: GROND Detection of the NIR Afterglow",
  "submitter": "Robert Filgas at MPI  <filgas@mpe.mpg.de>",
  "eventId": "GRB 100728B"
}