[vsnet-grb-info 28495] IPN Triangulation of a bright burst from SGR 1935+2154

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  30598
SUBJECT: IPN Triangulation of a bright burst from SGR 1935+2154
DATE:    21/08/07 02:29:56 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin at mail.ioffe.ru>

D. Svinkin, S. Golenetskii, D. Frederiks, A. Ridnaia,
A. Lysenko, and T. Cline on behalf of the Konus-Wind team,

K. Hurley, on behalf of the IPN,

S. Barthelmy, J. Cummings, H. Krimm, D. Palmer, and A. Tohuvavohu
on behalf of the Swift-BAT team, and

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,
report:

A bright, short-duration, soft burst has been observed by
Konus-Wind, INTEGRAL (SPI-ACS), and Swift (BAT), so far,
at about 536 s UT (00:08:56) on August 5.
The burst was outside the coded field of view of the BAT.

We have triangulated it to a Konus-BAT annulus centered at
RA(2000)=313.877 deg (20h 55m 31s) Dec(2000)=-20.391 deg (-20d 23' 28"),
whose radius is 46.762 +/- 0.249 deg (3 sigma) and
to a Konus-SPI-ACS annulus centered at
RA(2000)=310.504 deg (20h 42m 01s) Dec(2000)=-16.410 deg (-16d 24' 34"),
whose radius is 41.919 +/- 0.512 deg (3 sigma).

This localization may be improved.

The position of SGR 1935+2154 is inside the annuli
at 7.2 arcmin from the center line of the Konus-BAT annulus.

Given the positional coincidence of this burst with SGR 1935+2154, its 
time history, and softness of its spectrum  (as observed by Konus-Wind), 
we conclude this burst is likely originated from SGR 1935+2154.


A triangulation map is posted at
http://www.ioffe.ru/LEA/SGRs/210805_T00539/IPN/

The time history and spectrum will be given in forthcoming GCN Circulars.