TITLE:   GCN CIRCULAR
NUMBER:  13860
SUBJECT: GRB 121011A: Fermi GBM observation
DATE:    12/10/12 03:04:27 GMT
FROM:    Shaolin Xiong at UAH  <sx0002@uah.edu>

Shaolin Xiong (UAH), David Byrne (UCD) and Charles Meegan (USRA)
report on behalf of the Fermi GBM Team:

"At 11:15:25.70 UT on 11 October 2012, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 121011A (trigger 371646928 / 121011469),
which was also detected by the Swift/BAT (Racusin et al. 2012, GCN 13845)
and Fermi/LAT (M. Ohno et al. 2012, GCN 13859).
The GBM on-ground location is consistent with the Swift position.
The angle from the Fermi LAT boresight is ~56 degrees.
This burst was also independently detected by INTEGRAL SPI-ACS.

The GBM light curve shows a single peak with long tail
with a duration (T90) of about 66 s (10-1000 keV).
The time-averaged spectrum from T0+0.0 s to T0+67.6 s is
adequately fit by a power law function with an exponential
high-energy cutoff. The power law index is -1.09 +/- 0.07 and
the cutoff energy, parameterized as Epeak, is 1160 +/- 410 keV.

The event fluence (10-1000 keV) in this time interval is
(1.00 +/- 0.05)E-5 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+7.23 s in the 10-1000 keV band is 2.2 +/- 0.2 ph/s/cm^2.

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