{
  "bibcode": "2012GCN.13129....1S",
  "body": "V. Sudilovsky (MPE Garching), A. Nicuesa Guelbenzu (Tautenburg Observatory) and J. Greiner (MPE Garching) report on behalf of the GROND team:\n\nWe observed the field of GRB 120327A (Swift trigger 518731; Sbarufatti et al., GCN #13123) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at the 2.2 m MPI/ESO telescope at La Silla Observatory (Chile).\n\nObservations started at 03:34 UT, 39 minutes min after the GRB trigger, and are continuing. They were performed at an average seeing of 1.6\" and at an average airmass of 2.3.\n\nWe found a single point source consistent with both the UVOT (Sbarufatti et al, GCN #13123) and Liverpool telescope (Smith et al., GCN #13125) afterglow position.\n\nBased on the second of two 2.4 min of exposures in g'r'i'z' and 4 min in JHK, we estimate preliminary magnitudes (all in AB) at an observations midpoint 03:44 UT of\n\ng' = 18.6 +- 0.1 mag,\nr' = 17.5 +- 0.1 mag,\ni' = 17.2 +- 0.1 mag,\nz' = 17.0 +- 0.1 mag,\nJ  = 16.3 +- 0.1 mag, and\nH  = 15.9 +- 0.1 mag\n\nGiven magnitudes are calibrated against GROND zeropoints as well as 2MASS field stars and are not corrected for the expected Galactic foreground extinction corresponding to a reddening of E_(B-V)=0.34 mag in the direction of the burst (Schlegel et al. 1998). If this value is correct for the line-of-sight to this GRB, then the substantially reduced g-band flux suggests a redshift around 3.",
  "circularId": 13129,
  "createdOn": 1332826286000,
  "email": "vsudilov@mpe.mpg.de",
  "subject": "GROND observations of GRB 120327A",
  "submitter": "Vladimir Sudilovsky at MPE  <vsudilov@mpe.mpg.de>",
  "eventId": "GRB 120327A"
}