TITLE:   GCN CIRCULAR
NUMBER:  17389
SUBJECT: GRB 150203A: Fermi GBM observation
DATE:    15/02/03 11:09:45 GMT
FROM:    Hoi-Fung Yu at MPE  <sptfung@mpe.mpg.de>

V. Pelassa (UAH) and H.-F. Yu (MPE) report on behalf of the Fermi GBM Team:

"At 04:09:10.06 UT on 03 Feb 2015, the Fermi Gamma-Ray Burst Monitor
triggered and located GRB 150203A (trigger 444629353 / 150203173), which
was also detected by Swift (Ukwatta et al. 2015, GCN 17377). The GBM
on-ground location is consistent with the Swift position. The angle from
the Fermi LAT boresight is 97 degrees.

The GBM light curve shows a single pulse with a duration (T90) of
about 26 s (50-300 keV). The time-averaged spectrum from T0-2.048 s
to T0+ 27.648 s is well fit by a power law function with an exponential
high-energy cutoff. The power law index is -0.82 +/- 0.32 and the cutoff
energy, parameterized as Epeak, is 59 +/- 8 keV.

The event fluence (10-1000 keV) in this time interval is
(1.29 +/- 0.13)E-06 erg/cm^2. The 1.024-sec peak photon flux measured
starting from T0+13.952 s in the 10-1000 keV band is 1.8 +/- 0.3 ph/s/cm^2.

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