{
  "bibcode": "2019GCN.23830....1L",
  "body": "A. Y. Lien (GSFC/UMBC), P. D'Avanzo (INAF-OAB), J.D. Gropp (PSU),\nN. J. Klingler (PSU), N. P. M. Kuin (UCL-MSSL),\nF. E. Marshall (NASA/GSFC), D. M. Palmer (LANL), M. H. Siegel (PSU)\nand A. Tohuvavohu (PSU) report on behalf of the Neil Gehrels Swift\nObservatory Team:\n\nAt 01:39:30 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 190202A (trigger=887217).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 166.512, +9.388 which is \n   RA(J2000) = 11h 06m 03s\n   Dec(J2000) = +09d 23' 17\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve showed a complex\nstructure with a duration of about 30 sec.  The peak count rate\nwas ~4500 counts/sec (15-350 keV), at ~5 sec after the trigger. \n\nThe XRT began observing the field at 01:42:13.5 UT, 163.2 seconds after\nthe BAT trigger. XRT found a bright, uncatalogued X-ray source located\nat RA, Dec 166.5026, 9.3779 which is equivalent to:\n   RA(J2000)  = 11h 06m 0.62s\n   Dec(J2000) = +09d 22' 40.4\"\nwith an uncertainty of 5.9 arcseconds (radius, 90% containment). This\nlocation is 49 arcseconds from the BAT onboard position, within the BAT\nerror circle. No event data are yet available to determine the column\ndensity using X-ray spectroscopy. \n\nUVOT took a finding chart exposure of 126 seconds with the White filter\nstarting 172 seconds after the BAT trigger. There is a candidate afterglow in\nthe rapidly available 2.7'x2.7' sub-image at\n  RA(J2000)  =\t11:06:00.63 = 166.50262\n  DEC(J2000) = +09:22:36.6  =\t9.37683\nwith a 90%-confidence error radius of about 0.74 arc sec. This position is 3.9\narc sec. from the center of the XRT error circle. The estimated magnitude is\n16.01 with a 1-sigma error of about  0.14. No correction has been made for the\nexpected extinction corresponding to E(B-V) of 0.02. \n\nBurst Advocate for this burst is A. Y. Lien (amy.y.lien AT nasa.gov). \nPlease contact the BA by email if you require additional information\nregarding Swift followup of this burst. In extremely urgent cases, after\ntrying the Burst Advocate, you can contact the Swift PI by phone (see\nSwift TOO web site for information: /too.html.)",
  "circularId": 23830,
  "createdOn": 1549072691000,
  "email": "aaronb@swift.psu.edu",
  "subject": "GRB 190202A: Swift detection of a burst with an optical counterpart",
  "submitter": "Aaron Tohuvavohu at PSU/Swift  <aaronb@swift.psu.edu>",
  "eventId": "GRB 190202A"
}