{
  "bibcode": "2013GCN.15066....1V",
  "body": "K.Varela (MPE Garching), P.Afonso (American River College) and J.Greiner\n(MPE Garching)report on behalf of the GROND team :\n\nWe observed the field GRB 130803A (Swift trigger 565263; Page et al.,\nGCN 15059) simultaneously in g'r'i'z'JHKs with GROND (Greiner et al.2008,\nPASP 120, 405) mounted at the 2.2m MPG/ESO telescope at La Silla\nObservatory (Chile).\n\nObservations started at 23:13 UT on August 3, about 13.2 hours after\nthe trigger at a mean seeing of 1.8 arcsec and a mean airmass of 1.3. We\ndetect an extended source inside the enhanced 1.4'' XRT error circle\n(Swift webpage). This could be the GRB host, though at the moment no\nstatement about variability can be made.\n\nFor stacked integration times of 100 min. in JHK and ~ 125min in griz, we\npresent the following preliminary magnitudes and ULs at the 3 sigma level:\n\ng' = 25.6 +/- 0.4 mag,\nr' = 24.4 +/- 0.3 mag,\ni' = 23.8 +/- 0.2 mag,\nz' = 23.4 +/- 0.3 mag,\nJ > 23.2 mag,\nH > 22.5 mag, and\nK > 22.2 mag.\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) = 0.05 mag in the\ndirection of the burst (Schlegel et al. 1998).",
  "circularId": 15066,
  "createdOn": 1375595597000,
  "email": "kvarela@mpe.mpg.de",
  "subject": "GRB130803A: GROND detection of possible host",
  "submitter": "Karla Varela at MPE  <kvarela@mpe.mpg.de>",
  "eventId": "GRB 130803A"
}