TITLE:   GCN CIRCULAR
NUMBER:  21266
SUBJECT: GRB 170626A: Fermi GBM observation
DATE:    17/06/26 19:12:51 GMT
FROM:    Rachel Hamburg at UAH  <rkh0007@uah.edu>

R. Hamburg (UAH) and C. Meegan (UAH)
report on behalf of the Fermi GBM Team:

"At 09:37:21.95 UT on 26 June 2017, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 170626A (trigger 520162646 / 170626401)
which was also detected by the Swift/BAT
(Marshall et al. 2017, GCN 21264).
The GBM on-ground location is consistent with the Swift position.

The angle from the Fermi LAT boresight at the GBM trigger time is 75
degrees.

The GBM light curve shows one main peak
with a duration (T90) of about 12 s (50-300 keV).
The time-averaged spectrum from T0+0.00 to T0+13.6 s is
best fit by a Band function with Epeak = 94 +/- 2 keV,
alpha = -0.74 +/- 0.03, and beta = -2.7 +/- 0.1.

The event fluence (10-1000 keV) in this time interval is
(1.57 +/- 0.03)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+1.09 s in the 10-1000 keV band
is 37.2 +/- 0.5 ph/s/cm^2.

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