{
  "bibcode": "2006GCN..5878....1C",
  "body": "B. E. Cobb (Yale), part of the larger SMARTS consortium, reports:\n\nUsing the ANDICAM instrument on the 1.3m telescope at CTIO, we\nobtained optical/IR imaging of the error region of GRB 061121\n(GCN 5823, Page et al.) at several epochs.  At a mid-exposure\ntime of 2006-11-22 07:34 UT (16.2 hours post-burst), the afterglow\nis detected in a 36 minute I-band image with a magnitude of I=20.1+/-0.1.\nNo afterglow is detected in a 30 minute J-band image (with the same \nmid-exposure time) to a limiting magnitude of J>19.0+/-0.1.\n\nIn two subsequent epochs (mid-exposure times: 64.7 and 87.8 hours \npost-burst), 15 minute I and V exposures and 12 minute J and K exposures \nwere obtained.  At the position of the optical afterglow, a possibly \nextended source is detected in both V-band images.  The source does not \nappear to vary significantly between epochs and, therefore, may be the \nhost galaxy of GRB 061121 (also noted by Malesani et al., GCN 5877), \nwith a magnitude of V=22.4+/-0.2.  This source is detected, with low \nsignificance, in each I-band image. In a combined image of the 2 \nI-band epochs, the source has a magnitude of I=21.9+/-0.2.  The source is \nalso detected just slightly above the background in a combined J-band \nimage, which has a 3 sigma limiting magnitude of J>19.3+/-0.1.  \nThe source is not detected in the K-band, to a limiting magnitude \nof K>17.8+/-0.1.  All magnitudes are calibrated using 2MASS stars in IR \nand Landolt standard stars in the optical.",
  "circularId": 5878,
  "createdOn": 1164832061000,
  "email": "cobb@astro.yale.edu",
  "subject": "GRB 061121, SMARTS optical/IR observations",
  "submitter": "Bethany Cobb at Yale U  <cobb@astro.yale.edu>",
  "eventId": "GRB 061121"
}