{
  "bibcode": "2012GCN.13928....1C",
  "body": "B. E. Cobb (GWU), reports:\n\nUsing the ANDICAM instrument on the 1.3m telescope at CTIO, we obtained\noptical/IR imaging of the error region of GRB 121024A (GCN 13886,\nPagani et al.)  over several epochs (with mid-exposure times of\n2012-10-24 03:51 UT, 06:10 UT, 08:12 UT and 2012-10-25 06:53 UT).\nFor each epoch, several dithered images were obtained with\ntotal summed exposure times of 15 min in V and I and 12 min in\nJ and K.  For the final epoch, total exposure times were\n36 min in I and 30 min in J.\n\nThe fading afterglow of GRB 121024A (e.g. GCN 13887, Klotz et al.; GCN\n13888, Jelinek et al.; GCN 13891, Knust et al.) was detected with the\nfollowing magnitudes (or 3-sigma limits):\n\nmid-exposure\ntime\n(hours)         I mag            J mag            K mag\n0.90722       18.0 +/- 0.1   16.7 +/- 0.1   15.2 +/- 0.2\n3.23611       19.4 +/- 0.1   17.9 +/- 0.1   16.3 +/- 0.2\n5.27333       19.8 +/- 0.1   > 18.0           > 16.4\n27.95278      > 21.9          > 19.3           ...\n\n(Optical photometry is calibrated against USNO-B1.0 stars\nand IR photometry is calibrated against 2MASS stars in the field.)",
  "circularId": 13928,
  "createdOn": 1351544420000,
  "email": "bcobb@gwu.edu",
  "subject": "GRB 121024A: SMARTS optical/IR afterglow observations",
  "submitter": "Bethany Cobb at GWU  <bcobb@gwu.edu>",
  "eventId": "GRB 121024A"
}