TITLE:   GCN CIRCULAR
NUMBER:  23556
SUBJECT: IPN Triangulation of extremely bright short GRB 181222B
DATE:    18/12/25 10:29:28 GMT
FROM:    Dmitry Svinkin at Ioffe Institute  <svinkin@mail.ioffe.ru>

D. Svinkin, S. Golenetskii, R. Aptekar, D. Frederiks, A. Kozlova
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, report:

The short-duration, extremely bright GRB 181222B (Veres, GCN 23551)
was detected by Fermi (GBM trigger 567202302) and Konus-Wind
at about 72697 s UT (20:11:37).

We have triangulated it to a Konus-GBM annulus centered at 
RA(2000)=294.324 deg (19h 37m 18s) Dec(2000)=-23.694 deg (-23d 41' 39"), 
whose radius is 51.089 +/- 0.097 deg (3 sigma). The annulus reduces the 
area of the 3 sigma Fermi-GBM final position by about a factor of 130.

This annulus may be improved.

A triangulation map is posted at
ttp://www.ioffe.ru/LEA/GRBs/GRB181222_T72694/IPN

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