{
  "bibcode": "2021GCN.30501....1B",
  "body": "M. G. Bernardini (INAF-OAB), P. D'Avanzo (INAF-OAB),\nN. J. Klingler (GSFC/UMBC/CRESSTII), A. Y. Lien (GSFC/UMBC),\nA. Melandri (INAF-OAB), D. M. Palmer (LANL) and T. Sbarrato (INAF-OAB)\nreport on behalf of the Neil Gehrels Swift Observatory Team:\n\nAt 03:47:02 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 210725A (trigger=1061511).  Swift slewed immediately to the burst. \nThe BAT on-board calculated location is \nRA, Dec 215.363, -1.177 which is \n   RA(J2000) = 14h 21m 27s\n   Dec(J2000) = -01d 10' 36\"\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 10 sec.  The peak count rate\nwas ~1800 counts/sec (15-350 keV), at ~0 sec after the trigger. \n\nThe XRT began observing the field at 03:48:53.6 UT, 110.7 seconds after\nthe BAT trigger. Using promptly downlinked data we find a fading,\nuncatalogued X-ray source with an enhanced position: RA, Dec 215.3742,\n-1.1934 which is equivalent to:\n   RA(J2000)  = 14h 21m 29.81s\n   Dec(J2000) = -01d 11' 36.2\"\nwith an uncertainty of 1.9 arcseconds (radius, 90% containment). This\nposition may be improved as more data are received; the latest position\nis 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 in excess of the Galactic value (4.09 x\n10^20 cm^-2, Willingale et al. 2013), with an excess column of 3.9\n(+2.81/-2.40) x 10^21 cm^-2 (90% confidence). \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 114 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 expected\nextinction corresponding to E(B-V) of 0.046. \n\nBurst Advocate for this burst is M. G. Bernardini (grazia.bernardini AT brera.inaf.it). \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": 30501,
  "createdOn": 1627186041000,
  "email": "palmer@lanl.gov",
  "subject": "GRB 210725A: Swift detection of a burst",
  "submitter": "David Palmer at LANL  <palmer@lanl.gov>",
  "eventId": "GRB 210725A"
}