{
  "bibcode": "2006GCN..4611....1H",
  "body": "GRB 060121: Confirmation of NIR Afterglow\n\nF. Hearty (Colorado), M. Bayliss (Chicago), D. Q. Lamb (Chicago), G.\nGyuk (Chicago), M. Hammergren (Adler Planetarium), A. Puckett\n(Chicago), B. Ketzeback (APO), J. Barentine (APO), J. Dembicky (APO),\nR. McMillan (APO), and D. G. York (Chicago) report:\n\nWe have obtained a second-epoch observation of the afterglow (Malesani\net al. GCN 4561, Levan et al. GCN 4562) of GRB 060121, a bright\nshort/hard burst localized by HETE-2 (Arimoto et al. GCN 4550,\nPrigozhin et al. GCN 4551, Boer et al. GCN 4552), using NIC-FPS on the\nARC 3.5-meter telescope at Apache Point Observatory.  The second-epoch\nobservation began at 5.50 UT on 27 January (5.30 days after the burst)\nand ended at 6.92 UT on 27 January (5.35 days after the burst).  The\nobservation consisted of a series of 195 20-second exposures in Ks. \nUsing these exposures, we have constructed a stacked image of the GRB\nfield, corresponding to a 65-minute exposure.\n\nIn this image, we no longer detect the Ks-band source that we reported\nin GCN 4604.  Therefore, the source has clearly faded between the two\nobservations, confirming that it is the NIR afterglow of GRB 060121\n\nThe extended emission features that were visible in the first epoch \nimage about 1\" SE and about 1\" NE of the NIR afterglow are detected in \nthe second epoch image, but at lower significance than in the first \nepoch image because of somewhat poorer seeing.  We are therefore\nunable to establish with confidence the reality of either emission\nfeature.\n\nNIC-FPS is currently in its commissioning phase.",
  "circularId": 4611,
  "createdOn": 1138409905000,
  "email": "lamb@oddjob.uchicago.edu",
  "subject": "GRB 060121: Confirmation of NIR Afterglow",
  "submitter": "Don Lamb at U.Chicago  <lamb@oddjob.uchicago.edu>",
  "eventId": "GRB 060121"
}