Cool Stars 14 - Submitted Abstract # 71
This version created on 05 October 2006

X-ray flare modeling in the single giant HR 9024


Paola Testa, MIT
David Garcia-Alvarez, SAO
Fabio Reale, Universita' di Palermo
David Huenemoerder, MIT

We analyze a Chandra-HETGS observation of the single G-type giant HR
9024.  The high flux allows us to examine spectral line and continuum
diagnostics at high temporal resolution, to derive plasma parameters
(thermal distribution, abundances, temperature, ...).  A
time-dependent 1D hydrodynamic loop model with semi-length 5*10^11 cm
(~R_star/2), and impulsive footpoint heating triggering the flare,
satisfactorily reproduces the observed evolution of temperature and
emission measure, derived from the analysis of the strong continuum
emission.  The observed characteristics of the flare appear to be
common features in very large flares in active stars (also pre-main
sequence stars), possibly indicating some fundamental physics for
these very dynamic and extreme phenomena in stellar coronae.

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