Bibcode
Huenemoerder, David; Nichols, Joy S.; DePalma, David; Garcia-Alvarez, David; Schulz, Norbert S.; Canizares, Claude R
Referencia bibliográfica
American Astronomical Society, AAS Meeting #224, #421.01
Advertised on:
6
2014
Número de citas
0
Número de citas referidas
0
Descripción
The highly modulated optical light curve of HD 79826 (spectral type G5)
was discovered in the Chandra 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 Chandra 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 thesaturation
limit of Lx/Lbol = 0.001. 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 will further 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.
Acknowledgments: This work was supported by NASA through the Smithsonian
Astrophysical Observatory (SAO) contract SV3-73016 for the Chandra X-Ray
Center and Science Instruments.