{
  "bibcode": "2015GCN.18313....1S",
  "body": "S. Schmidl (TLS Tautenburg), F. Knust, and J. Greiner (both MPE Garching)\nreport on behalf of the GROND team:\n\nWe observed the field of GRB 150911A (Swift trigger 655262; Starling et\nal, GCN 18280) simultaneously in g'r'i'z'JHK with GROND (Greiner et al.\n2008,PASP 120, 405) mounted at the 2.2m MPG telescope at ESO La Silla\nObservatory (Chile).\n\nObservations started on September 12, 2015, at 05:59 UT, 11.3 hrs after\nthe GRB trigger. They were performed at an average seeing of 2.2\" and at an\naverage airmass of 1.8.\n\nWe do not detect a source within the 1.7\" Swift-XRT error circle\nreported by Goad et al. (GCN 18283).\n\nBased on total exposures of 33 minutes in g'r'i'z'and 43 minutes in\nJHK, at a midtime of 12.1 hrs after the burst, we measure the following\npreliminary upper limits (AB magnitude system):\n\ng'> 24.1 mag,\nr'> 23.8 mag,\ni'> 23.2 mag,\nz'> 22.8 mag,\nJ > 21.6 mag,\nH > 21.0 mag, and\nK > 19.9 mag.\n\nGiven upper limits are calibrated against GROND zeropoints as well as\n2MASS field stars and are not corrected for the expected Galactic\nforeground extinction corresponding to a reddening of E_(B-V) = 0.32 mag\nin the direction of the burst (Schlegel et al. 1998).",
  "circularId": 18313,
  "createdOn": 1442254444000,
  "email": "schmidl@tls-tautenburg.de",
  "subject": "GRB 150911A: GROND Upper Limits",
  "submitter": "Sebastian Schmidl at TLS Tautenburg  <schmidl@tls-tautenburg.de>",
  "eventId": "GRB 150911A"
}