{
  "bibcode": "2012GCN.13688....1S",
  "body": "V. Sudilovsky (MPE Garching), S. Klose (TLS Tautenburg), and J. Greiner \n(MPE Garching) report on behalf of the GROND team:\n\nWe observed the field of GRB 120819A (Swift trigger 531428; Beardmore et \nal., GCN 13681) simultaneously in g'r'i'z'JHKs with GROND (Greiner et \nal. 2008, PASP 120, 405) mounted at the 2.2 m MPG/ESO telescope at La \nSilla Observatory (Chile).\n\nObservations started at 23:46 UT on 2012-08-19, 10.5 hrs after the GRB \ntrigger. Based on co-added images spanning 2 hours taken at a mean \nairmass of 1.3 and seeing of 1.6\", we confirm the presence of the NOT \nafterglow candidate (Malesani et al., GCN 13683). We derive preliminary \nmagnitudes (all AB system) of this source:\n\n   g' = 23.7 +- 0.1\n   r' = 23.1 +- 0.1\n   i' = 22.5 +- 0.1\n   z' = 22.2 +- 0.1\n   J  = 21.5 +- 0.3\n   H  > 20.2\n   Ks > 20.1\n\nWe note that although these magnitudes do not suggest fading, the large \nuncertainties from the USNO calibration used by Malesani et al. do not \npreclude this possibility.\n\nThe consistency with the enhanced XRT position (Evans et al., GCN \n13684), combined with the power-law like SED, confirm that this source \nis the afterglow of GRB 120819A.\n\nThe g' band detection does not suggest substantial Ly-alpha or dust \neffects, implying that the redshift of this burst is likely smaller than \n3.0.\n\nThe magnitudes are derived based on GROND zeropoints (g'r'i'z') and \n2MASS stars (JHK). The magnitudes are not corrected for the expected \nGalactic reddening along the line of sight of E_(B-V)= 0.16 mag \n(Schlegel et al. 1998).",
  "circularId": 13688,
  "createdOn": 1345447750000,
  "email": "vsudilov@mpe.mpg.de",
  "subject": "GRB 120819A: GROND afterglow confirmation",
  "submitter": "Vladimir Sudilovsky at MPE  <vsudilov@mpe.mpg.de>",
  "eventId": "GRB 120819A"
}