TITLE:   GCN CIRCULAR
NUMBER:  21285
SUBJECT: GRB 170629A: Fermi GBM observation
DATE:    17/06/29 22:03:09 GMT
FROM:    Rachel Hamburg at UAH  <rkh0007@uah.edu>

R. Hamburg (UAH), E. Bissaldi (Politecnico & INFN Bari), and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 12:53:31.63 UT on 29 June 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 170629A (trigger 520433616 / 170629537),
which was also detected by the Swift/BAT
(Cholden-Brown et al. 2017, GCN 21283).
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 24
degrees.

The GBM light curve consists of a single emission episode
with a duration (T90) of about 28 s (50-300 keV).
The time-averaged spectrum from T0-0.00 s to T0+12.29 s is
best fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.1 +/- 0.1 and
the cutoff energy, parameterized as Epeak, is 126 +/- 10 keV.

The event fluence (10-1000 keV) in this time interval is
(3.3 +/- 0.1)E-06 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+8.70 s in the 10-1000 keV band
is 6.0 +/- 0.3 ph/s/cm^2.

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