{
  "bibcode": "2010GCN.11430....1N",
  "body": "A. Nicuesa Guelbenzu, (Tautenburg Obs.), P.Schady and J.Greiner (MPE  \nGarching) report on behalf of the GROND team:\n\nWe observed the field of GRB 101201A (Swift trigger 439595-6, Fermi  \nGBM 312890511; Cummings et al., GCN #11429) simultaneously in  \ng'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405) mounted at  \nthe 2.2 m MPI/ESO telescope at La Silla Observatory (Chile).\n\nObservations started during twilight, at 00:36 UT on 2010-12-02, 14.6  \nhours after the GRB trigger, and are continuing. They were performed  \nat an average seeing of better than 0.8\" and at an average airmass of 1.\n\nWe found a bright, uncatalogued point source within the 2 arcmin Swift- \nBAT error circle at\n\nRA (J2000.0) = 00:07:52.19 s\n\nDEC (J2000.0) = -16:11: 05.42\n\nwith an uncertainty of 0.5\" in each coordinate.\n\nThe source is detected in all optical and NIR GROND filters and had a  \npreliminary AB magnitude or r' = 19.67+/-0.01 10 mins after the start  \nof our observations. The source faded by ~0.3 magnitudes within the  \nfirst 1.5 hours of GROND observations, leading us to conclude that  \nthis is the afterglow of GRB101201A.\n\nThe detection of the source in the reddest GROND filter puts an upper  \nlimit on the redshift of this GRB of z < ~3. Given magnitudes are  \ncalibrated against USNO zeropoints and are not corrected for the  \nexpected Galactic foreground extinction corresponding to a reddening  \nof E_(B-V)=0.02 mag in the direction of the burst (Schlegel et al.  \n1998).",
  "circularId": 11430,
  "createdOn": 1291258173000,
  "email": "pschady@mpe.mpg.de",
  "subject": "GRB 101201A: GROND Detection of the Optical/NIR Afterglow",
  "submitter": "Patricia Schady at MPE/Swift  <pschady@mpe.mpg.de>",
  "eventId": "GRB 101201A"
}