GCN Circular 20239

M. Stanbro (UAH) and E. Bissaldi (Politecnico & INFN Bari)
report on behalf of the Fermi GBM Team:

"At 01:32:28.08 UT on 06 December 2016, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 161206A (trigger 502680752/161206064).
The on-ground calculated location, using the GBM trigger
data, is RA = 0.94, DEC = -34.02 (J2000 degrees),
with an uncertainty of 1 degree (radius, 1-sigma containment,
statistical only; there is additionally a systematic
error which we have characterized as a core-plus-tail model, with 90% of
GRBs having a 3.7 deg error and a small tail suffering a larger than 10 deg
systematic error [Connaughton et al. 2015, ApJS, 216, 32]).

The angle from the Fermi LAT boresight at the GBM trigger time is 63
degrees.

The GBM light curve shows multiple peaks
with a duration (T90) of about 34 s (50-300 keV).
The time-averaged spectrum from T0-9 s to T0+25 s is
best fit by a Band function with Epeak = 309 +/- 15 keV,
alpha = -0.85 +/- 0.02, and beta = -2.11 +/- 0.05.

The event fluence (10-1000 keV) in this time interval is
(3.92 +/- 0.04)E-05 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+9.6 s in the 10-1000 keV band
is 13.5 +/- 0.3 ph/s/cm^2.


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