  In early October 2008, the Soft Gamma Repeater SGRJ1550 - 5418 (1E 1547.0 -
5408, AXJ155052 - 5418, PSR J1550 - 5418) became active, emitting a series of
bursts which triggered the Fermi Gamma-ray Burst Monitor (GBM) after which a
second especially intense activity period commenced in 2009 January and a
third, less active period was detected in 2009 March-April. Here we analyze the
GBM data all the bursts from the first and last active episodes. We performed
temporal and spectral analysis for all events and found that their temporal
characteristics are very similar to the ones of other SGR bursts, as well the
ones reported for the bursts of the main episode (average burst durations \sim
170 ms). In addition, we used our sample of bursts to quantify the systematic
uncertainties of the GBM location algorithm for soft gamma-ray transients to <
8 deg. Our spectral analysis indicates significant spectral evolution between
the first and last set of events. Although the 2008 October events are best fit
with a single blackbody function, for the 2009 bursts an Optically Thin Thermal
Bremsstrahlung (OTTB) is clearly preferred. We attribute this evolution to
changes in the magnetic field topology of the source, possibly due to effects
following the very energetic main bursting episode.

High Energy Astrophysical Phenomena