[vsnet-grb-info 6524] Konus-Wind observations of new SGR 0501+4516

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8132
SUBJECT: Konus-Wind observations of new SGR 0501+4516
DATE:    08/08/25 18:15:54 GMT
FROM:    Dmitry Frederiks at Ioffe Institute  <fred at mail.ioffe.ru>

S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin,
D. Frederiks, P. Oleynik, D. Svinkin, M. Ulanov
and T. Cline, on behalf of the Konus-Wind team report:


On August 23-25 Konus-Wind detected in triggered mode four bursts from
new SGR 0501+4516 (Holland et al. GCN 8112, Barthelmy et al. GCN 8113).

First two of these bursts were localized by Swift (Palmer et al. ATel #1678).
The others had the same estimated ecliptic latitude, temporal structure
and spectral parameters and so we can with great degree of probability
attribute them to the new SGR.

The burst lightcurves vary from a single pulse with a duration of less
than 50 ms to more complex structure lasting for ~500ms.
The spectra of the bursts demonstrate a pronounced spectral evolution
and are well fitted (in the 20-200 keV range) by the power law with
exponential cutoff. The bursts energetics in this range is summarized
in the table below. The high values of the peak fluxes, comparable
to ones for the strongest recurrent bursts from the other known SGRs
may imply the lower distance to the source.

--------------------------------------------------------------------
Date     UT               Fluence       Peak flux (2ms)
                           erg/cm2       erg/cm2/s
--------------------------------------------------------------------
080823a  04:47:46.194(*)  --            --
080823b  11:27:32.652     4x10-6        7x10-5
080824   01:17:55.316     2.5x10-5      2x10-4
080825   04:48:27.445     3.3x10-6      1.6x10-4
--------------------------------------------------------------------
(*) data are incomplete at this time

The Konus-Wind light curves are available at Ioffe website:
http://www.ioffe.ru/LEA/SGRs/080823_T41252/
http://www.ioffe.ru/LEA/SGRs/080824_T04675/
http://www.ioffe.ru/LEA/SGRs/080825_T17307/