The variable WC 9 star HD 164270 revisited : a close binary with a precessing disk ?
Abstract
Five independent sets of photometric data now support the cyclic variability claimed for this cool, carbon-sequence Wolf-Rayet star. With a period of 1.75404 days, the continuum intensity varies in a double wave per cycle with an amplitude of about 0.03 mag in the visible, and a tendency to increase at shorter wavelengths. As noted previously, the emission-line radial velocities tend to show a single wave per cycle, whose low amplitude is compatible with the presence of a neutron-star (NS) companion. The recently announced deep, broad, eclipse-like variations with a possible period of tens of years may be caused by a precessing disk associated with the WR-NS system. If so, an unseen third body of moderate mass must be invoked as the motor for this precession. The alternative possibility of nonradial pulsations to explain the photometric and spectroscopic variations cannot be excluded.
- Publication:
-
Publications of the Astronomical Society of the Pacific
- Pub Date:
- November 1986
- DOI:
- Bibcode:
- 1986PASP...98.1170M
- Keywords:
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- Binary Stars;
- Stellar Physics;
- Variable Stars;
- Wolf-Rayet Stars;
- Astronomical Photometry;
- Carbon Stars;
- Cool Stars;
- Free Electrons;
- Light Curve;
- Stellar Magnitude;
- Astrophysics