{
  "bibcode": "2010GCN.10706....1L",
  "body": "A.J. Levan (U. Warwick), A. Cucchiara  (PSU), N.R. Tanvir (U.\nLeicester), D. Fox (PSU) report on behalf of a larger collaboration:\n\n\"We obtained two epochs of observations of GRB 100420A (Baumgartner\net al. GCN 10628) using Gemini-North/NIRI. Our first epoch consisted\nof 540s of observations in each of YJH and K and began at April 20\n13:24 UT, approximately 8.2 hours after the burst. Our second epoch\nwas obtained at April 22 14:27 ~57 hours after the burst.\n\nWithin the refined XRT error circle we find a single object in our\nfirst epoch K-band observation. The object has a location of\n\nRA(J2000) 19:44:30.57\nDec(J2000) 55:46:10.0\n\nwith an error of 0.3\" in each axis. It has a magnitude of K~21 in\nour first epoch observation, but has faded below our 3-sigma detection\nlimit of K~22 in the second epoch. We therefore identify this source\nas the infrared afterglow of GRB 100420A.\n\nThe source is not significantly detected in our J or H-band observations \nto preliminary limiting magnitudes of H>21.5, J>22.5 (3 sigma). However, \nbecause of the relative faintness of the K-band observations these limits\nare not constraining in terms of high-z and dust extinguished\nafterglow models\"",
  "circularId": 10706,
  "createdOn": 1272578507000,
  "email": "A.J.Levan@warwick.ac.uk",
  "subject": "GRB 100420A: Gemini discovery of infrared afterglow",
  "submitter": "Andrew Levan at U.of Leicester  <A.J.Levan@warwick.ac.uk>",
  "eventId": "GRB 100420A"
}