TITLE:   GCN CIRCULAR
NUMBER:  15104
SUBJECT: GRB 130816A: Fermi GBM observation
DATE:    13/08/16 21:10:16 GMT
FROM:    Gerard Fitzpatrick at UCD  <gerard.fitzpatrick@ucdconnect.ie>

G. Fitzpatrick (UCD) and G. Younes (NASA/USRA)
report on behalf of the Fermi GBM Team:

At 01:46:28.52 UT on 16 August 2013, the Fermi Gamma-Ray Burst Monitor
triggered and located the precursor to GRB130816A (trigger
398310391/130816074)
which was detected by the Swift/BAT (Holland et al. 15097, GCN 14527).
The GBM on-ground location is consistent with the Swift position.

The GBM light curve consists of the precursor and the main pulse
with a duration (T90) of about 32  s (50-300 keV).
The time-averaged spectrum from T0+23 s to T0+32 s is
adequately fit by a simple power law function with index -1.83 +/- 0.05.

The event fluence (10-1000 keV) in this time interval is
(1.3 +/- 0.1)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+27 s in the 10-1000 keV band is 1.9 +/- 0.2 ph/s/cm^2.

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