TITLE:   GCN CIRCULAR
NUMBER:  19476
SUBJECT: IPN Triangulation of GRB 160530A
DATE:    16/05/31 15:21:11 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. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo,
and C. Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team, report:

The long-duration, very bright GRB 160530A (COSI detection Tomsick GCN 
Circ. 19473) has been detected by Konus-Wind and INTEGRAL (SPI-ACS), so 
far, at about 25426 s UT (07:03:46).

We have triangulated it to a Konus-SPI-ACS annulus centered at 
RA(2000)=50.332 deg (03h 21m 20s)  Dec(2000)=+12.855 deg (+12d 51' 19"), 
whose radius is 77.066 +/- 0.305 deg (3 sigma).

The COSI position reported by Tomsick (GCN Circ. 19473) is
consistent with the annulus. The annulus combined with the COSI
(90% confidence) error circle produces the following preliminary error
box:
----------------------------------
RA(2000), deg   Dec(2000), deg
----------------------------------
Center:
118.942        -25.764
Corners:
118.644        -25.659
118.758        -26.966
119.239        -25.868
119.707        -24.768
----------------------------------
The error box area is 3404.3 sq. arcmin, and its maximum
dimension is 2.36 deg (the minimum one is 18 arcmin).
The Sun distance was about 67 deg.

This box may be improved.

A triangulation map is posted at
http://www.ioffe.ru/LEA/GRBs/GRB160530_T25426/IPN/

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