[vsnet-grb-info 13818] IPN triangulation of GRB 130821A

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15132
SUBJECT: IPN triangulation of GRB 130821A
DATE:    13/08/29 18:34:05 GMT
FROM:    Kevin Hurley at UCBerkeley/SSL  <khurley at ssl.berkeley.edu>

K. Hurley and J. Goldsten, on behalf of the MESSENGER NS GRB team,

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

A. von Kienlin, X. Zhang, A. Rau, V. Savchenko, E. Bozzo, and C.
Ferrigno, on behalf of the INTEGRAL SPI-ACS GRB team,

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

S. Barthelmy, J. Cummings, N. Gehrels, H. Krimm, and D. Palmer, on behalf of
the Swift-BAT team, and

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

GRB 130828A (GCN 15128, 15129, 15130) has been observed by Fermi,
INTEGRAL (SPI-ACS), Konus-Wind, MESSENGER GRNS, Suzaku, and Swift
(outside the coded field of view), so far.  We have triangulated it to
an annulus centered at RA(2000)=340.597 deg (22 h 42 m 23 s),
Dec(2000)=-9.971 deg (-9 d 58 m 17 s), whose radius is 86.782 +/- 0.092
degrees (3 sigma).  This annulus intersects the Fermi-LAT 1 sigma error
circle (GCN 15128) to form an error box whose area (280 sq.  arcmin.) is 
about 3.6 times smaller than that of the LAT error circle , and whose
corners are
         RA(2000)                    Dec(2000)
     259.541=17 h 18 m 09 s      27.843= 27 d 50 ' 34 "
     259.649=17 h 18 m 35 s      28.254= 28 d 15 ' 13 "
     259.722=17 h 18 m 53 s      27.716= 27 d 42 ' 56 "
     259.875=17 h 19 m 30 s      28.297= 28 d 17 ' 50 "

A map has been posted at ssl.berkeley.edu/ipn3/130828A.

Some improvement in this triangulation is possible.