GCN Circular 8370

E. Bissaldi (MPE) reports on behalf of the Fermi GBM Team: 


"At 13:10:23 UT on 12 October 2008, the Fermi Gamma-ray Burst Monitor
triggered and located GRB 081012 (trigger 245509824/081012549), which
was also detected by Swift (Stroh et al., GCN 8361
Not found
 
 
).
The on-ground calculated location, using the Fermi GBM trigger data, is 
RA = 30.9, Dec = -19.2 (equivalent to J2000 
02h 04m, -19d 12'), with a statistical uncertainty of 6.8 degrees 
(radius, 1-sigma containment; there is additionally a systematic 
error which is currently estimated to be 2 to 3 degrees). 
This position is 1.7 deg from the Swift XRT position
(Kennea et al., GCN 8364
Not found
 
 
). The angle from the Fermi LAT boresight 
to the Swift position is 61 degrees.

GRB 081012 is single peaked with an estimated T90 (25-900 keV) 
of about 30 s. The time-averaged spectrum from T0-3.1 s to T0+7.2 s 
is well fit by a power law function with an exponential 
high-energy cutoff.  The cutoff energy, parameterized as
Epeak, is 360 +/- 70 keV with a power law index of -0.31 +/- 0.23.
It can also be fit by using a Band function with Epeak = 320 +/- 80 keV
and beta = -2.4 +/- 0.7. However alpha is poorly constrained.

The fluence (25-900 keV) for the power law model with
exponential cutoff is (3.8 +/- 0.4)E-06 erg/cm2. 
The 1 sec peak photon flux measured starting from T0+4.1 in 
the 25-900 keV band is 2.0 +/- 0.2 ph/s/cm2.


The spectral analysis results presented above are preliminary;
the final results will be published in the Fermi GBM GRB Catalog."