TITLE:   GCN CIRCULAR
NUMBER:  30803
SUBJECT: IPN triangulation of a bright burst from SGR 1935+2154
DATE:    21/09/10 20:59:57 GMT
FROM:    Anna Ridnaia at Ioffe Institute  <ridnaia@mail.ioffe.ru>

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

K. Hurley, on behalf of the IPN,

A. Goldstein, M. S. Briggs, and C. Wilson-Hodge
on behalf of the Fermi-GBM team, and

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

A bright, short-duration, soft burst has been observed by
Fermi (GBM), Konus-Wind, and Swift (BAT), so far,
at about 2747 s UT (00:45:47) on September 10.
The burst was outside the coded field of view of the BAT.

We have triangulated it to a Konus-GBM annulus centered at
RA(2000)=326.594 deg (21h 46m 22s)  Dec(2000)=-14.741 deg (-14d 44' 28"),
whose radius is 48.801 +/- 0.199 deg (3 sigma).

This localization may be improved.

The position of SGR 1935+2154 lies inside the annulus at 0.7 arcmin
from its center line.

Given the positional coincidence of this burst with SGR 1935+2154,
its time history, softness of its spectrum (as observed by Konus-Wind),
and reported bursting activity (Xiao et al., GCN Circ. 30797),
we conclude this burst is likely originated from SGR 1935+2154.

A triangulation map is posted at
http://www.ioffe.ru/LEA/SGRs/210910_T02750/IPN/

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