{
  "createdOn": 1740513629766,
  "subject": "GRB 250225B: Swift detection of a burst",
  "circularId": 39473,
  "submittedHow": "email",
  "bibcode": "2025GCN.39473....1W",
  "body": "M. A. Williams (PSU), S. Dichiara (PSU), R. Gupta (NASA GSFC),\nH. A. Krimm (NSF), M. J. Moss (GSFC), K. L. Page (U Leicester) and\nD. M. Palmer (LANL) report on behalf of the Neil Gehrels Swift\nObservatory Team:\n\nAt 19:39:13 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated GRB 250225B (trigger=1291459).  Swift could not slew immediately\ndue to an observing constraint.\nThe BAT on-board calculated location is \nRA, Dec 306.145, -41.484 which is \n   RA(J2000) = 20h 24m 35s\n   Dec(J2000) = -41d 29' 03\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve showed a multiple-peaked\nstructure (well-separated peaks at T+1, T+60, T+110) with a total\nduration of about 120 sec. The peak count rate was ~13000 counts/sec \n(15-350 keV), at ~1 sec after the trigger.\n\nDue to a Moon observing constraint, Swift cannot slew to the BAT\nposition until 05:11 UT on 2025 February 26. There will thus be no XRT\nor UVOT data for this trigger before this time.\n\nWe note the presence of the Emission-line Galaxy ESO 340-26\nin the BAT error box.  This is a bright (B=14.8, R=10.9) extended\n(1.4 arcmin) galaxy at z ~ 0.018 .\n\nBurst Advocate for this burst is M. A. Williams (mjw6837 AT 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 250225B",
  "submitter": "David Palmer at LANL <palmer@lanl.gov>"
}