GCN Circular 20660

O.J. Roberts (USRA/NASA) and B. Mailyan (UAH)
report on behalf of the Fermi GBM Team:

"At 02:47:36.58 UT on February 10th 2017, the Fermi
Gamma-Ray Burst Monitor triggered and located
GRB 170210A (trigger 508387661 / 170210116). The
on-ground calculated location using the GBM trigger
data is,

RA = 232.56, DEC = -58.59 (J2000 degrees), equivalent to
J2000 15h 30m, -58d 35',

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 initial angle from the Fermi-LAT boresight to the GBM
ground-location is 109 degrees.

The GBM light curve shows a long burst with multiple
episodes of bright emission over a duration (T90) of about
79 s (50-300 keV). The time-averaged spectrum from T0+9 s
to T0+84 s is best fit by a Band function with
alpha= -0.90 +/- 0.02, beta= -2.28 +/- 0.08 and Epeak
is 361.5 +/- 14.1 keV.

The event fluence (10-1000 keV) in this time interval is
(1.10 +/- 0.2) E-04 erg/cm^2. The 1s peak photon flux
measured starting from T0+41.7 s in the 10-1000 keV band is
32.8 +/- 0.6 ph/s/cm^2.

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