{
  "bibcode": "2013GCN.14364....1S",
  "body": "V. Sudilovsky (MPE Garching), A. Nicuesa Guelbenzu (TLS Tautenburg) and\nJ.Greiner (MPE Garching) report on behalf of the GROND team:\n\nWe observed the field of GRB 130408A (Swift trigger 553132; Lien et al.,\nGCN 14361) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008,\nPASP 120, 405) mounted at the 2.2 m MPG/ESO telescope at La Silla\nObservatory (Chile).\n\nObservations started at 23:22 UT on April 8th, 1.5 hrs after the GRB\ntrigger. They were performed at an average seeing of 1.0 and at an average\nairmass of 1.0.\n\nBased integrations of 260s in the optical and 240s in the NIR taken at a\nmid-time of UT 23:34, we detect the variable source reported by Melandri\net al. (GCN 14362) and Siegel & Lien (GCN 14363), with preliminary\nmagnitudes (all AB):\n\ng' = 21.0 +- 0.1,\nr' = 19.7 +- 0.1,\ni' = 19.1 +- 0.1,\nz' = 18.8 +- 0.1,\nJ = 18.0 +- 0.1,\nH = 17.8 +- 0.1, and\nK > 17.0.\n\nThe large r-g color implies a redshift of z>3. Observations are ongoing.\n\nGiven magnitudes are calibrated against GROND zeropoints in g'r'i'z' and\n2MASS field stars in JHK. They are not corrected for the Galactic\nforeground extinction corresponding to a reddening of E_(B-V)= 0.26 mag in\nthe direction of the burst (Schlegel et al. 1998).",
  "circularId": 14364,
  "createdOn": 1365467933000,
  "email": "kann@tls-tautenburg.de",
  "subject": "GRB 130408A: GROND detection of the afterglow",
  "submitter": "Alexander Kann at TLS Tautenburg  <kann@tls-tautenburg.de>",
  "eventId": "GRB 130408A"
}