{
  "bibcode": "2009GCN..9026....1U",
  "body": "Adria C. Updike (Clemson University), Robert Filgas (Tautenburg Obs.),\nThomas Kruehler, Jochen Greiner (MPE Garching), and Sheila McBreen\n(University College Dublin) report on behalf of the GROND team:\n\nWe observed the field of GRB 090323 (Fermi trigger 259459364 / 090323002;\nOhno et al., GCN #9021) simultaneously in g'r'i'z'JHK with GROND (Greiner\net al. 2008, PASP 120, 405) mounted at the 2.2 m ESO/MPI telescope at La\nSilla Observatory (Chile).\n\nObservations started at 02:50 UT on March 24, 26 hours and 48 minutes time\nafter the GRB trigger, and are continuing. They were performed at an\naverage seeing of 1.3\" and at an average airmass of 1.8.\n\nWe found a single point source within the 2.7\" Swift-XRT error circle\nreported by Kennea et al. (GCN #9024) at\n\nRA (J2000.0) = 12h 42m 50.29s\n\nDEC (J2000.0) = +17d 03' 11.6\"\n\nwith an uncertainty of 0.5\".\n\nBased on the first 8 min of total exposures in g'r'i'z' J H Ks, we\nestimate preliminary magnitudes (all in AB system) of\n\ng' = 21.64 +/- 0.07 mag,\n\nr' = 20.03 +/- 0.03 mag,\n\ni' = 19.64 +/- 0.02 mag,\n\nz' = 19.39 +/- 0.02 mag,\n\nJ = 19.24 +/- 0.02 mag,\n\nH = 18.86 +/- 0.02 mag, and\n\nK = 18.58 +/- 0.03 mag\n\nGiven magnitudes are calibrated against GROND zeropoints as well\nas 2MASS field stars and are not corrected for the expected Galactic\nforeground extinction corresponding to a reddening of E_(B-V)= 0.02 mag in\nthe direction of the burst (Schlegel et al. 1998).\n\nBased on the given magnitudes, we find a photometric redshift of z = 4.0\n+/- 0.3.",
  "circularId": 9026,
  "createdOn": 1237871201000,
  "email": "aupdike@clemson.edu",
  "subject": "GRB 090323: GROND Detection of the Afterglow and Photo-z",
  "submitter": "Adria C. Updike at Clemson U  <aupdike@clemson.edu>",
  "eventId": "GRB 090323"
}