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GCN Circular 9310

Subject
GRB 090429C: Fermi GBM detection
Date
2009-04-30T21:44:51Z (15 years ago)
From
Sheila McBreen at MPE <smcbreen@mpe.mpg.de>
Sheila McBreen (UCD/MPE) reports on behalf of
the Fermi GBM Team:

"At 12:43:25.70  UT on 29 April 2009, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 090429C (trigger 262701807  / 090429530).

The on-ground calculated location, using the GBM trigger
data, is RA = 261.4, DEC = +55.5 (J2000 degrees,
equivalent to 17 h 26 m, +55 d 30 '), with an uncertainty
of 4.9 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 112 degrees.

The GBM light curve consists of two pulses
with a duration of about 13 s (8-1000 keV).
The time-averaged spectrum from T0-2 s to T0+11 s is
adequately fit by a simple power law function
with index -1.43 +/- 0.04 (chi squared 513 for 471 d.o.f.).

The event fluence (8-1000 keV) in this time interval is
(3.7 +/- 0.1)E-6 erg/cm^2. The 0.256 sec peak photon flux measured
starting from T0+0.768 s in the 8-1000 keV band
is 6.7 +/- 0.4 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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