TITLE:   GCN CIRCULAR
NUMBER:  8251
SUBJECT: IPN Triangulation and Energy Spectrum of GRB080916C
DATE:    08/09/16 22:36:31 GMT
FROM:    Kevin Hurley at UCBerkeley/SSL  <khurley@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, and
T. Cline on behalf of the Konus-Wind team

E. Bellm, D. M. Smith, R. P. Lin, J. McTiernan, R. Schwartz, C. Wigger, W.
Hajdas, and A. Zehnder, on behalf of the RHESSI GRB team, 

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

E. Del Monte, I. Donnarumma, Y. Evangelista, M. Feroci, I. Lapshov,
F. Lazzarotto, L. Pacciani, M. Galli, and M. Marisaldi, on behalf 
of the AGILE Team, 

report:

GRB080916C (Goldstein and van der Horst, GCN 8245; Tajima et
al., GCN 8246) was also observed by AGILE (MCAL, SuperAGILE, and ACS -
but not localized), RHESSI, INTEGRAL (SPI-ACS), Konus-Wind,
and MESSENGER.  A preliminary triangulation gives a long,
narrow error box centered at RA, Dec = 119.830, -56.790 degrees
(0.2 degrees from the center of the LAT error circle), whose
corners are:

 RA(2000)    DEC(2000)             
  119.486    -62.130
  120.126    -62.702
  119.901    -50.632
  120.321    -51.274

A figure is posted at ssl.berkeley.edu/ipn3/080916C.

Using the RHESSI data between 100 keV and 17 MeV, the time-integrated
spectrum for the 62-second interval beginning at 00:12:46 UT can be described
by a cutoff power law with alpha ~ -1.2 +/- 0.3, Epeak ~ 1100 +/- 500 keV,
and fluence ~ (9.0 +/- 1.6) x 10^-5 ergs/cm^2 (100 keV - 10 MeV).


Both the triangulation and the energy spectrum can be substantially
improved.