TITLE:   GCN CIRCULAR
NUMBER:  29365
SUBJECT: IPN triangulation of a bright burst from SGR 1935+2154
DATE:    21/01/28 20:39:47 GMT
FROM:    Anna Ridnaia at Ioffe Institute  <ridnaia@mail.ioffe.ru>

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

K. Hurley, on behalf of the IPN,

and

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

The bright, short-duration, soft burst
(GECAM detection: Huang et al., GCN Circ. 29363)
was detected by GECAM, Konus-Wind, and Swift (BAT)
at about 24617 s UT (06:50:17) on January 27.
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)=315.213 deg (21h 00m 51s)  Dec(2000)=-14.116 deg (-14d 06' 56"),
whose radius is 41.658 +/- 0.174 deg (3 sigma).

The position of SGR 1935+2154 lies inside the annulus at 3.5 arcmin
from its center line.

Given the positional coincidence (initially suggested in GCN 29363) 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/210127_T24616/IPN/

The Konus-Wind time history and spectrum will be given in a forthcoming
GCN Circular.