Astronomy and Astrophysics – Astronomy
Scientific paper
Sep 2002
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002dps....34.4202c&link_type=abstract
American Astronomical Society, DPS Meeting #34, #42.02; Bulletin of the American Astronomical Society, Vol. 34, p.916
Astronomy and Astrophysics
Astronomy
4
Scientific paper
Gamma Cephei is a sub-giant in a long-period (P> 40 yrs) binary system. Walker et al. (1992) reported short-term periodic radial velocity (RV) variations in the residuals after subtracting the velocity contribution due to the stellar companion. These residual variations had a period of 2.52 yr period and were consistent with a Jupiter-mass companion in orbit at approximately 2 AU from the primary. Walker et al. dismissed this hypothesis because they detected weak variations in the Ca II 8662Å emission line index with the same period as ``planet''. We present precise stellar radial velocity variations for γ Cep made at McDonald Observatory that extend the time base of observations to more than 20 years. The combined dataset shows that the planet period has been present and coherent over the past 20 years. The long lived nature of the residual RV variations make it unlikely that they are due to stellar rotation. We also present Ca II S-index measurements that show no periodic variations at the 2.5 yr period. Furthermore, no appropriate period is found in (contemporaneous) Hipparcos photometry. We conclude that a planet with a projected mass of 1.25 MJupiter in orbit 1.8 AU from the primary star is the most likely explanation for the short term RV variations in γ Cep. This planet is in a binary star system with the shortest binary period found so far and should provide an interesting case study for understanding how binary stars influence the planet formation process.
Campbell Bel
Cochran William D.
Endl Michael
Hatzes Artie P.
Paulson Diane B.
No associations
LandOfFree
A Planetary Companion to the Binary Star Gamma Cephei does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A Planetary Companion to the Binary Star Gamma Cephei, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A Planetary Companion to the Binary Star Gamma Cephei will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1045896