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Summary: Flares as Heating Agents of Active Late-Type Stellar
Coronae?
M. Audard 1;2 , M. Gudel 1;2 , J. J. Drake 3 , V. L. Kashyap 3 , E. F. Guinan 4
Abstract.
We present results from a study of statistical
ares on active late-type
stars (spectral type F to M) using Extreme Ultraviolet Explorer (EUVE )
archival data. We used several methods to investigate the
are rate dis-
tributions as a function of observed EUV and X-ray emitted thermal en-
ergy (found to be dN=dE / E ); we include stars with di erent spectral
types, and di erent intrinsic parameters such as the projected rotational
velocity, the rotation period, the X-ray luminosity and the ratio LX =L bol .
We used a
are identi cation method based on count distributions of
\quiescent" emission as a function of temporal bin size. Di erent types
of ts to the cumulative and di erential distributions were performed.
The derived power-law indices suggest a weak dependence on spectral
type. F and G stars are characterized by > 2, while K and M stars
have best- t values below 2, although > 2 cannot be excluded. We
test several correlations between the above intrinsic parameters and the
power-law indices or the occurrence rates of
ares with energies larger
than 10 32 ergs.
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