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GCN Circular 13429

GRB 120709A: Fermi GBM detection
2012-07-10T23:19:36Z (12 years ago)
Sylvain Guiriec at UAH <>
Sylvain Guiriec (GSFC), Valerie Connaughton (UAH)
and Michael Briggs (UAH)
report on behalf of the Fermi GBM Team:

"At 21:11:40.37 UT on 09 July 2012, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 120709A (trigger 120709883 / 120709.883).

The on-ground calculated location, using the GBM trigger
data, is RA = 320.02, DEC = -47.87 (J2000 degrees,
equivalent to 21h20m04, -47d52'12), with an uncertainty
of  1.70 degrees (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which is currently estimated to be 2 to 3 degrees).

The angle from the Fermi LAT boresight is 22 degrees.
The burst was also seen by the LAT (Kocevski et al., GCN 13423)

The GBM light curve consists of 3 intense peaks
with a duration (T90) of about 30 s (50-300 keV).
The time-averaged spectrum from T0 s to T0+41s is
adequately fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.22 +/- 0.03 and
the cutoff energy, parameterized as Epeak, is 449 +/- 55 keV

The event fluence (10-1000 keV) in this time interval is
(1.43 +/- 0.04)E-5 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+11.65 s in the 10-1000 keV band
is 11.4897 +/- 0.2869 ph/s/cm^2.

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