Gamma Cephei: Rotation or Planetary Companion? (original) (raw)

ADS

;

• Bohlender, David A. ;
• Walker, Andrew R. ;
• Irwin, Alan W. ;
• Yang, Stephenson L. S. ;
• Larson, Ana

Abstract

In 1988 Gamma Cep was reported as a single-line, long-period spectroscopic binary with short-term periodic (P = 2.7 yr) residuals which might be caused by a Jupiter-mass companion. Eleven years of data now give a 2.52 yr (K = 27 m/s) period and an indeterminate spectroscopic binary period of not less than 30 yr. While binary motion induced by a Jupiter-mass companion could still explain the periodic residuals, Gamma Cep is almost certainly a velocity variable yellow giant because both the spetrum and (R - I) color indices are typical of luminosity class III. T eff and the trigonometric parallax give 5.8 solar radii independently.

Publication:

The Astrophysical Journal

Pub Date:

September 1992

DOI:

10.1086/186524

Bibcode:

1992ApJ...396L..91W

Keywords:

• Binary Stars;
• Companion Stars;
• Radial Velocity;
• Stellar Rotation;
• Variable Stars;
• Chromosphere;
• Extrasolar Planets;
• G Stars;
• Rotational Spectra;
• Stellar Activity;
• Stellar Spectra;
• Astrophysics;
• PLANETS AND SATELLITES: GENERAL;
• STARS: BINARIES: SPECTROSCOPIC;
• STARS: CHROMOSPHERES;
• STARS: ROTATION;
• STARS: VARIABLES: OTHER MISCELLANEOUS