Bibcode
Huenemoerder, D. P.; Nichols, Joy S.; DePalma, David; Garcia-Alvarez, David; Schulz, Norbert S.
Referencia bibliográfica
18th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, Proceedings of the conference held at Lowell Observatory, 8-14 June, 2014. Edited by G. van Belle and H.C. Harris., pp.517-526
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1
2015
Número de citas
0
Número de citas referidas
0
Descripción
The highly modulated optical light curve of HD 79826 (spectral types
G5+M5) was discovered in the \chan guide-star light curves, indicating a
period of about 0.5 days, a strong and migrating distortion wave, and a
shallow eclipse. We subsequently obtained simultaneous \chan high
resolution X-ray spectra and optical photometry, along with
contemporaneous ground-based photometry and spectra. X-ray rotational or
eclipse modulation was totally obscured by X-ray variability and flares.
X-ray spectra are characterized by coronal emission near the saturation
limit of L_{x}/L_{bol} = 10^{mthree}. Optical spectra show extremely
rotationally broadened features, variable with orbital phase. Optical
light curves show the modulation to be not only rapidly migrating in
phase, but also of variable amplitude. We characterize the X-ray
emission through measurements of line widths, velocities, and fluxes,
and provide coronal plasma models. This star is near or at the limits of
dynamo saturation, and since it is partially eclipsing, has potential to
be well characterized in terms of fundamental stellar parameters.