  We model in detail a flare observed on Proxima Centauri with the EPIC-PN on
board XMM-Newton at high statistics and high time resolution and coverage.
Time-dependent hydrodynamic loop modeling is used to describe the rise and peak
of the light curve, and a large fraction of the decay, including its change of
slope and a secondary maximum, over a duration of more than 2 hours. The light
curve, the emission measure and the temperature derived from the data allow us
to constrain the loop morphology and the heating function and to show that this
flare can be described with two components: a major one triggered by an intense
heat pulse injected in a single flaring loop with half-length ~1.0 10^{10} cm,
the other one by less intense heat pulses released after about 1/2 hour since
the first one in related loop systems, probably arcades, with the same
half-length. The heat functions of the two loop systems appear be very similar:
an intense pulse located at the loop footpoints followed by a low gradual decay
distributed in corona. The latter result and the similarity to at least one
solar event (the Bastille Day flare in 2000) indicate that this pattern may be
common to solar and stellar flares, in wide generality.
