[AAVSO-HEN] Trigger 321551: Continued Large Flaring of SGR 0501+4516

[grb at aavso.org]

The following is a GCN Circular circulated via the AAVSO network.
For an archive and more information on circulars visit:
http://lheawww.gsfc.nasa.gov/docs/gamcosray/legr/bacodine/gcn3_archive.html

TITLE:   GCN CIRCULAR
NUMBER:  8124
SUBJECT: Trigger 321551: Continued Large Flaring of SGR 0501+4516
DATE:    08/08/23 11:56:13 GMT
FROM:    David Palmer at LANL  <palmer at lanl.gov>

N. Gehrels (NASA/GSFC), J. Mao (INAF-OAB), D. M. Palmer (LANL),
M. Perri (ASDC), B. Preger (ASDC), G. Stratta (ASDC) and
L. Vetere (PSU) report on behalf of the Swift Team:

At 11:27:35 UT, the Swift Burst Alert Telescope (BAT) triggered on
a large flare from the newly discovered SGR 0501+4516 (trigger=321551). 
Swift was already observing this source location due to its previous. 
The BAT on-board calculated location is 
RA, Dec 75.265, +45.281 which is 
   RA(J2000) = 05h 01m 04s
   Dec(J2000) = +45d 16' 52"
with an uncertainty of 3 arcmin (radius, 90% containment, including 
systematic uncertainty).  The BAT light curve showed a roughly 
flat-topped structure with a duration of about 0.256 sec. 
The peak count rate was ~300k counts/sec (15-350 keV), 
at ~0.2 sec after the trigger. 

The BAT burst response algorithm causes a TDRSS alert only
when a known source exceeds twice its previous fluence, so
additional large flares may have occurred since the 
previously-reported large flare at 4:47:48 UT.  Ground
processing of Malindi data will be required to report
on other activity by this source.