{
  "bibcode": "2013GCN.14191....1K",
  "body": "F. Knust (MPE Garching), A. Nicuesa Guelbenzu (TLS Tautenburg)\nand J. Greiner (MPE Garching) report on behalf of the  GROND team:\n\nWe observed the field of GRB 130206A (Swift trigger 547918; De Pasquale\net al.,GCN 14181) simultaneously in g'r'i'z'JHK with GROND (Greiner et al.\n2008, PASP 120, 405) mounted at the 2.2m MPG/ESO telescope at La Silla\nObservatory (Chile).\n\nThe first observations started at 01:10 UT on 07 Feb 2013, 6.5 hrs after\nthe GRB trigger, and a second epoch was taken at 7:47 UT on 8 Feb 2013.\nThese observations were performed at an average seeing of 1.4/1.0 arcsec\nand at an average airmass of 1.3/1.4.\n\nWe detect three sources within the 5.6 arcsec Swift-XRT error circle\n(Beardmore et al., GCN 14188), at positions:\n\nSource 1\nRA (2000.0) = 09h 21m 30.45s\nDecl. (2000.0) = -58d 11' 34.7\"\n\nSource 2\nRA (2000.0) = 09h 21m 30.10s\nDecl. (2000.0) = -58d 11' 36.5\"\n\nSource 3\nRA (2000.0) = 09h 21m 30.14s\nDecl. (2000.0) = -58d 11' 41.2\"\n\nwith an uncertainty of 0.5\" in each coordinate.\n\nFor the aforementioned three sources, the preliminary photometry does\nnot show any variability. Image subtraction between the two epochs\nhas revealed no residuals either.\n\nBased on exposures of 42 min in g'r'i'z' and  54 min in JHK,\nwe do not detect the afterglow  within the 5.6\" XRT error circle\nto the following  3-sigma upper limits (AB system):\n\n\ng' > 24.7,\nr' > 24.6,\ni' > 23.8,\nz' > 23.8,\nJ > 21.6,\nH > 21.2 and\nK > 20.6\n\nThe given limits are derived based on calibrating the images against GROND\nzeropoints and 2MASS field stars and are not corrected for the Galactic\nforeground extinction corresponding to a reddening of E_(B-V)= 0.5 in the\ndirection of the burst (Schlegel et al. 1998).",
  "circularId": 14191,
  "createdOn": 1360351231000,
  "email": "ana@tls-tautenburg.de",
  "subject": "GRB 130206A: GROND Observations",
  "submitter": "Ana Nicuesa at TLS Tautenburg  <ana@tls-tautenburg.de>",
  "eventId": "GRB 130206A"
}