TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  3474
SUBJECT: Konus-Wind observation of GRB 050525
DATE:    05/05/25 11:28:56 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>

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

A long bright GRB 050525 (Swift-BAT trigger=130088: GCN 3466,3467)
triggered Konus-Wind at 176.704 s UT (00:02:56.704).
As observed by Konus-Wind, it had a duration of ~11.5 s,
fluence (7.84 +/- 0.06)10-5 erg/cm2, 
peak flux on 16-ms time scale (8.7 +/- 0.7)10-6 erg/cm2 s 
(both in the 20 keV - 1 MeV energy range).

In ~2800 s after trigger, Konus-Wind detected 
even more intense burst. Because it was detected
during data readout, only time history in the G2
window (74-295 keV) with 3-s time resolution is available.
It had a duration of ~20 s and fluence 25100 counts in
74-295 keV energy range (the fluence of the trigger burst
was 8500 counts in the same energy range). Assuming 
it had the same spectrum as the trigger burst,
the energy fluence can be estimated as ~2.3x10^-4 erg/cm2.

Whether the second burst relates to the first one
or it is different GRB accidentaly registered close to
the trigger burst can be clarified by data
from other instruments
(but the chance to register two very bright bursts so close
to each other seems to be poor).

The time-integrated spectrum of the GRB 050525
is well fitted by a power law with
exponential roloff model:
dN/dE ~ E^alpha exp(-E/E0)
with alpha = -1.10 +/- 0.05,
and E0 = 93.6 +/- 5.3 keV.
The peak energy Ep = 84.1 +/- 1.7 keV.