{
  "bibcode": "2015GCN.17419....1S",
  "body": "T. Schweyer (MPE Garching), S. Schmidl (TLS Tautenburg), and J. Greiner\n(MPE Garching) report on behalf of the GROND team:\n\nWe observed the field of GRB 150206A (Swift trigger 630019; Hagen et al.,\nGCN 17413) 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 00:32 UT on February 07, 2015, 10 hrs after the\nGRB trigger. They were performed at an average seeing of 1.4\" and at an\naverage airmass of 1.7.\n\nWe detect the optical aftergow canditate reported by Hagen et al. (GCN\n17413).\n\nBased on total exposures of 8.8 minutes in g'r'i'z' and 8.0 minutes in\nJHK, at a midtime of 10.3 hrs after the burst, we measure the following\npreliminary magnitudes and upper limits (all AB magnitude system):\n\ng' = 22.6 +/- 0.2 mag,\nr' = 21.9 +/- 0.1 mag,\ni' = 21.2 +/- 0.1 mag,\nz' = 20.8 +/- 0.1 mag,\nJ = 20.0 +/- 0.2 mag,\nH > 20.2 mag, and\nK > 19.4 mag.\n\nThe magnitudes are calibrated against GROND zeropoints and 2MASS field\nstars and are not corrected for the Galactic foreground extinction\ncorresponding to a reddening of E_(B-V)= 0.02 in the direction of the\nburst (Schlegel et al. 1998).",
  "circularId": 17419,
  "createdOn": 1423275277000,
  "email": "schmidl@tls-tautenburg.de",
  "subject": "GRB 150206A: GROND afterglow observations",
  "submitter": "Sebastian Schmidl at TLS Tautenburg  <schmidl@tls-tautenburg.de>",
  "eventId": "GRB 150206A"
}