{
  "subject": "GRB 240419A: Swift detection of a burst",
  "submittedHow": "email",
  "submitter": "Simone Dichiara at Pennsylvania State University <sbd5667@psu.edu>",
  "bibcode": "2024GCN.36169....1S",
  "circularId": 36169,
  "body": "\nM. H. Siegel (PSU), S. Dichiara (PSU), R. Gupta (NASA/GSFC),\nJ. A. Kennea (PSU), S. Laha (GSFC/UMBC), D. M. Palmer (LANL) and\nM. A. Williams (PSU) report on behalf of the Neil Gehrels Swift\nObservatory Team:\n\nAt 01:48:01 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 240419A (trigger=1222955).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 94.568, -45.011 which is \n   RA(J2000) = 06h 18m 16s\n   Dec(J2000) = -45d 00' 40\"\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 4 sec.  The peak count rate\nwas ~1500 counts/sec (15-350 keV), at ~1 sec after the trigger. \n\nThe XRT began observing the field at 01:49:51.1 UT, 110.1 seconds after\nthe BAT trigger. Using promptly downlinked data we find a fading,\nuncatalogued X-ray source located at RA, Dec 94.53468, -45.00073 which\nis equivalent to:\n   RA(J2000)  = 06h 18m 08.32s\n   Dec(J2000) = -45d 00' 02.6\"\nwith an uncertainty of 3.5 arcseconds (radius, 90% containment). This\nlocation is 92 arcseconds from the BAT onboard position, within the BAT\nerror circle. This position may be improved as more data are received;\nthe latest position is available at https://www.swift.ac.uk/sper. \n\nA power-law fit to a spectrum formed from promptly downlinked event\ndata gives a column density consistent with the Galactic value of 6.63\nx 10^20 cm^-2 (Willingale et al. 2013). \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 113 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 100% of\nthe XRT error circle. The typical 3-sigma upper limit has been about 19.6 mag. \nThe 8'x8' region for the list of sources generated on-board covers 100% of the\nXRT error circle. The list of sources is typically complete to about 18 mag. No\ncorrection has been made for the expected extinction corresponding to E(B-V) of\n0.069. \n\nBurst Advocate for this burst is M. H. Siegel (siegel AT swift.psu.edu). \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/)\n\n",
  "eventId": "GRB 240419A",
  "createdOn": 1713492197527
}