{
  "bibcode": "1999GCN...350....1T",
  "body": "G. B. Taylor (NRAO), D. A. Frail (NRAO) and S. R. Kulkarni (Caltech)\nreport:\n\n\"We have continued to monitor the four radio sources detected (GCN\n308) within the RXTE/IPN localization (GCN 298) for GRB 990506. Some\ntime between May 8 and May 22 one of these sources dropped from 0.54\nmJy at 8.4 GHz to below our detection limit (30-40 microJy), while the\nrest remained constant. In order to confirm or reject the possibility\nthat this object is an Active Galactic Nucleus we initiated a\nmulti-frequency monitoring program.  We have recently analyzed the\ndata taken between May 22 and June 12 and found that the source\nremains undetectable.  Our data lead us to conclude that an AGN\nidentification is unlikely, and that the transient source, hereafter\nVLA J115450.1-2640.6, is the radio afterglow from GRB 990506.  VLA \nJ115450.1-2640.6 was located at (J2000) R.A.= 11:54:50.14 (+/-0.04),\nDec.=-26:40:35.2 (+/-0.8). We urge all optical/IR observers to\nre-investigate their images at this precise location for any sign of a\nvariable object.\"\n\nThis message is citeable.",
  "circularId": 350,
  "createdOn": 929471325000,
  "email": "gtaylor@aoc.nrao.edu",
  "subject": "GRB 990506 Radio Transient",
  "submitter": "Greg Taylor at NRAO  <gtaylor@aoc.nrao.edu>",
  "eventId": "GRB 990506"
}