TITLE: GCN CIRCULAR NUMBER: 41172 SUBJECT: Swift detection of the Soft Gamma Repeater PSR J1647-4552 DATE: 25/07/26 23:21:53 GMT FROM: David Palmer at LANL <palmer@lanl.gov> S. Dichiara (PSU), R. Gupta (NASA GSFC) and D. M. Palmer (LANL) report on behalf of the Neil Gehrels Swift Observatory Team: At 2025-07-26 22:49:05 UT, the Swift Burst Alert Telescope (BAT) triggered and located Soft Gamma Repeater (SGR) PSR J1647-4552 (trigger=1337165). For this previously-known source, Swift is configured to NOT automatically slew to the location. The BAT on-board calculated location is RA, Dec 251.779, -45.871 which is RA(J2000) = 16h 47m 07s Dec(J2000) = -45d 52' 14" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). This position is within 34 arcseconds of the SGR catalogued location. The BAT light curve showed a single spike structure (at the 64 ms resolution of the immediately-available lightcurve) with a duration of about 128 ms sec. The peak count rate was ~2700 counts/sec (15-350 keV), at ~0 sec after the trigger. There have been 12 previous detections of bursts from this source by BAT, most recently in Feb 2020. The detections have come singly or in clusters of 2-3 within minutes to hours. View this GCN Circular online at https://gcn.nasa.gov/circulars/41172. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...