TITLE:   GCN CIRCULAR
NUMBER:  9700
SUBJECT: IPN Triangulation of bright GRB 090720B 
DATE:    09/07/22 16:08:03 GMT
FROM:    Valentin Pal'shin at Ioffe Inst  <val@mail.ioffe.ru>

S. Golenetskii, R. Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, and T.
Cline on behalf of the Konus-Wind team,

A. von Kienlin, A. Rau, and K. Hurley on behalf of the
INTEGRAL SPI-ACS GRB team,

M. Marisaldi, F. Fuschino, C. Labanti, M. Galli, G. Di Cocco
on behalf of the AGILE team,

K. Yamaoka, M. Ohno, Y. Fukazawa, T. Takahashi, M. Tashiro, Y. Terada,
T. Murakami, K. Makishima, and Y. Hanabata on behalf of the Suzaku-WAM 
team, and

V. Connaughton, M. Briggs, and C. Meegan, on behalf of the Fermi GBM
team, report:

Suzaku-WAM, Konus-Wind, AGILE-MCAL, and INTEGRAL (SPI-ACS) observed the 
bright GRB 090720B at about 17:02:57 UT (the Fermi/GBM trigger 
269802178/090720710: Burgess et al. GCN 9698).
We have triangulated this burst to a Konus-GBM annulus centered at 
RA(2000)=274.434 (18h 17m 44s)  Dec(2000)=-23.965 (-23d 57' 54"), whose 
radius is  60.824 +/- 0.031 (3 sigma).
Triangulation of the Konus-SPI-ACS gives an annulus centered
at RA(2000)=274.426 (18h 17m 42s)  Dec(2000)=-18.772 (-18d 46' 19"), 
whose radius is  64.910 +/- 0.252 (3 sigma).

Together, these 2 annuli yield a 3-sigma error box whose center and 
corners are:
-----------------------------------------------
      RA(2000), deg              Dec(2000), deg
-----------------------------------------------
Center:
   201.609 (13h 26m 26s)   -55.000 (-55d 00' 01")
Corners:
   201.763 (13h 27m 03s)   -59.798 (-59d 47' 54")
   201.580 (13h 26m 19s)   -58.693 (-58d 41' 36")
   201.793 (13h 27m 10s)   -50.725 (-50d 43' 29")
   201.823 (13h 27m 17s)   -51.627 (-51d 37' 36")
-----------------------------------------------

The error box area is 0.500 sq. deg and may be refined.

The GBM on-ground location (Burgess et al. GCN 9698) is consistent with 
the IPN box.

A map is posted at http://www.ioffe.ru/LEA/GRBs/GRB090720_T61379/IPN/
showing GBM contours (statistical) and best-fit position (star),
and the IPN annuli (solid lines with centers dot-dashed).

This map will also be posted at http://ssl.berkeley.edu/ipn3/090720B .

The IPN localization may be improved.