TITLE:   GCN CIRCULAR
NUMBER:  18704
SUBJECT: GRB 151210B: Fermi GBM observation
DATE:    15/12/16 16:11:47 GMT
FROM:    Peter Veres at UAH  <veresp@gmail.com>

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

"At  00:59:16.643 UT on 10 December 2015, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 151210B (trigger 471401960 / 151210041)
which was also detected by the CALET Gamma-Ray Burst Monitor
(Sakamoto et al. 2015, GCN 18701).

The on-ground calculated location, using the GBM trigger
data, is RA = 294.0, DEC = -42.7 (J2000 degrees,
equivalent to 19 h 36 m, 42 d 42 '), with an uncertainty
of 3.4 degrees (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 13 degrees.


The GBM light curve shows an initial peak followed by a weaker emission episode
with a duration (T90) of about 37.6 s (50-300 keV).
The time-averaged spectrum from T0-4 s to T0+39 s is
adequately fit by a power law function with an exponential
high-energy cutoff.  The power law index is -1.45 +/- 0.08 and
the cutoff energy, parameterized as Epeak, is 306 +/- 94 keV.

The event fluence (10-1000 keV) in this time interval is
(5.8 +/- 0.4)E-6 erg/cm^2. The 1-sec peak photon flux measured
starting from T0+0.7 s in the 10-1000 keV band
is 2.4 +/- 0.2 ph/s/cm^2.


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