{
  "bibcode": "2019GCN.24147....1M",
  "body": "M. J. Moss (George Washington University), S. D. Barthelmy (GSFC),\nJ.D. Gropp (PSU), J. A. Kennea (PSU), N. J. Klingler (PSU),\nN. P. M. Kuin (UCL-MSSL), A. Y. Lien (GSFC/UMBC),\nF. E. Marshall (NASA/GSFC), K. L. Page (U Leicester),\nM. H. Siegel (PSU) and A. Tohuvavohu (PSU) report on behalf of the\nNeil Gehrels Swift Observatory Team:\n\nAt 22:55:29 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 190422A (trigger=899979).  Swift did not slew until ~T+8 min \ndue to an observing constraint. \nThe BAT on-board calculated location is \nRA, Dec 182.124, -60.238 which is \n   RA(J2000) = 12h 08m 30s\n   Dec(J2000) = -60d 14' 15\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve showed a complex\nstructure with a duration of at least 220 sec, where data are currently\navailable. The peak count rate based on the available data\nwas ~2000 counts/sec (15-350 keV), at ~175 sec after the trigger. \n\nThe XRT began observing the field at 23:04:18.5 UT, 529.3 seconds after\nthe BAT trigger. Using promptly downlinked data we find an uncatalogued\nX-ray source located at RA, Dec 182.03650, -60.22311 which is\nequivalent to:\n   RA(J2000)  = 12h 08m 08.76s\n   Dec(J2000) = -60d 13' 23.2\"\nwith an uncertainty of 3.8 arcseconds (radius, 90% containment). This\nlocation is 165 arcseconds from the BAT onboard position, within the\nBAT error circle. This position may be improved as more data are\nreceived; the latest position is available at\nhttp://www.swift.ac.uk/sper.  We cannot determine whether the source is\nfading at the present time. \n\nA power-law fit to a spectrum formed from promptly downlinked event\ndata gives a column density in excess of the Galactic value (8.59 x\n10^21 cm^-2, Willingale et al. 2013), with an excess column of 1.1\n(+1.25/-0.89) x 10^22 cm^-2 (90% confidence). \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 531 seconds after the BAT trigger. No credible afterglow candidate has\nbeen found in the initial data products. The 2.7'x2.7' sub-image covers none of\nthe XRT error circle. The 8'x8' region for the list of sources generated\non-board covers 100% of the XRT error circle. The list of sources is typically\ncomplete to about 18 mag. No correction has been made for the large, but\nuncertain, extinction expected. \n\nThis source lies within the current (Sector 11) field-of-view of TESS camera 2. \n\nBurst Advocate for this burst is M. J. Moss (mikejmoss3 AT gmail.com). \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: http://www.swift.psu.edu/)",
  "circularId": 24147,
  "createdOn": 1555974941000,
  "email": "palmer@lanl.gov",
  "subject": "GRB 190422A: Swift detection of a burst",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>",
  "eventId": "GRB 190422A"
}