{
  "bibcode": "2005GCN..4013....1N",
  "body": "J. Norris (GSFC), L. Barbier (GSFC), D. Burrows (PSU), A. Cucchiara (PSU),\nJ. Cummings (GSFC/NRC), N. Gehrels (GSFC), M. Goad (U. Leicester),\nO. Godet (U. Leicester), S.T. Holland (GSFC/USRA), J. Kennea (PSU),\nF. Marshall (GSFC), D. Palmer (LANL), T. Sakamoto (GSFC/NRC),\non behalf of the Swift team:\n\nAt 19:55:50 UT Swift-BAT triggered and located GRB 050922C (Trigger=156467)\nand immediately slewed.  The BAT on-board calculated position is RA,Dec= \n317.391d, -8.772d {21h 09m 34s, -08d 46' 17\"} (J2000) with an uncertainty\nof 3 arcmin (radius, 90% containment, stat+sys).  The TDRSS light curve \nshows an intense GRB with a rising precursor starting at T-5 seconds, \nfollowed by 5-second long main peak surmounted by three spikes.  The third \nand most intense spike has a maximum count rate at T+1 sec of 15,000 \ncounts/sec (15-350 keV).\n\nXRT began observing the field at 19:57:38 UT, 108 seconds after the BAT\ntrigger. XRT performed an onboard centroid and found a previously\nuncataloged fading source in the field of view at the following coordinates:\n\nRA(J2000):  21:09:33.4,\nDec(J2000): -8:45:30.5,\n\nwith an estimated uncertainty of 8 arcseconds radius (90% containment). This\nposition is 49 arcseconds from the BAT position and within 4.5 arcsec of the\noptical transient reported by Rykoff et al. (GCN circ 4011 [mistitled]).\n\nUVOT began observing at 111 sec after the trigger.  The small UVOT TDRSS \nimage does not overlap the XRT error circle. However, the full-field UVOT \nsource list contains a bright, uncataloged source within the XRT error\ncircle.  We estimate the V magnitude at 15.5 +- 0.5 uncorrected for \nextinction.  The V-band extinction in this field is A_V = 0.34 mag.\n\n[GCN OPS NOTE(22sep05): Per author's request, the Subject-line\nwas changed from \"050822\" to \"050922\".]",
  "circularId": 4013,
  "createdOn": 1127423145000,
  "email": "jayc@milkyway.gsfc.nasa.gov",
  "subject": "GRB 050922C: Swift detection of a bright burst",
  "submitter": "Jay R. Cummings at NASA/GSFC/Swift  <jayc@milkyway.gsfc.nasa.gov>",
  "eventId": "GRB 050922C"
}