{
  "bibcode": "2012GCN.13438....1E",
  "body": "J. Elliott (MPE Garching), S. Klose (TLS Tautenburg), and J. Greiner (MPE \nGarching) report on behalf of the GROND team:\n\nWe observed the field of GRB 120711A (INTEGRAL trigger 6599: Gotz et al., \nGCN 13434; Bozzo et al., GCN 13435; MAXI/GSC detection: Serino et al., GCN \n13436; Fermi/GBM trigger 363667496 / 120711115: Gruber & Pelassa, GCN \n13427) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP \n120, 405) mounted at the 2.2m MPG/ESO telescope at La Silla Observatory \n(Chile).\n\nObservations started on July 11, 08:34 UT, 5.8 hrs after the trigger as \nsoon the location became visible at La Silla. The afterglow (Lacluyze et \nal., GCN 13430, 13433; Zheng, GCN 13432) is clearly detected in all bands.\n\nFor an exposure of 8 min in JHK and 7.66 min in g'r'i'z', at an average \nairmass of 2.5 and an average seeing of 2\".0, we measure the following \npreliminary AB magnitudes\n\n    g' = 20.9  +/- 0.1\n    r' = 20.2  +/- 0.1\n    i' = 19.6  +/- 0.1\n    z' = 19.4  +/- 0.1\n    J  = 18.6  +/- 0.1\n    H  = 18.2  +/- 0.1\n    K  = 18.0  +/- 0.1\n\nThe SED, after correction for Galactic reddening along the line of sight \n(E(B-V)=0.09 mag; Schlegel et al. 1998), can be described by a power law \n(beta ~ 1.4) with a reduced flux in the g-band, suggesting a photometric \nredshift of about 3. We note that also the PROMPT afterglow light curve \n(http://skynet.unc.edu/grb/grb120711a.png) supports a drop-out in the blue \nbands.\n\nMagnitudes are derived based on GROND zeropoints (g'r'i'z') and 2MASS \nstars (JHK).",
  "circularId": 13438,
  "createdOn": 1342005109000,
  "email": "klose@tls-tautenburg.de",
  "subject": "GRB 120711A: GROND photometric redshift",
  "submitter": "Sylvio Klose at TLS Tautenburg  <klose@tls-tautenburg.de>",
  "eventId": "GRB 120711A"
}