{
  "bibcode": "2014GCN.16099....1V",
  "body": "K. Varela, C. Delvaux (both MPE Garching), A. Nicuesa Guelbenzu (TLS\nTautenburg), and J. Greiner (MPE Garching) report on behalf of the GROND\nteam:\n\nWe observed the field of GRB 140413A (Swift trigger 595616; D'Elia et al.,\nGCN #16098) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008,\nPASP 120, 405) mounted at the 2.2 m MPG telescope at La Silla Observatory\n(Chile).\n\nObservations started at 00:13 UT on 13 April 2014, less than 5 min after\nthe GRB trigger, and are continuing. They are performed at a mean airmass\nof 1.9 and a mean seeing of 0.9\".\n\nWe find a single point source within the 5.8\" Swift/XRT error circle at\ncoordinates\n\n   RA(J2000)  =  04:21:49.23\n   Dec(J2000) = -51:10:58.0.\n\nAt a midtime of 00:17 UT we measure the following preliminary AB magnitudes:\n\nr' = 20.2 +/- 0.1,\ni' = 19.6 +/- 0.1,\nz' = 19.3 +/- 0.1.\n\nThe source is also visible in g. At present we cannot decide if the source\nis fading. Data processing is still ongoing, observations are continuing.\n\nGiven magnitudes are calibrated against GROND zeropoints as well as 2MASS\nfield stars and are not corrected for the expected Galactic foreground\nextinction corresponding to a reddening of E_(B-V)=0.02 mag in the\ndirection of the burst (Schlegel et al. 1998).",
  "circularId": 16099,
  "createdOn": 1397353046000,
  "email": "ana@tls-tautenburg.de",
  "subject": "GRB 140413A: GROND afterglow candidate",
  "submitter": "Ana Nicuesa at TLS Tautenburg  <ana@tls-tautenburg.de>",
  "eventId": "GRB 140413A"
}