Thursday, December 7, 2017

The Most Eccentric Planet Orbiting a Giant Star

The Pan-Pacific Planet Search. VII. The Most Eccentric Planet Orbiting a Giant Star


Wittenmyer et al


Radial velocity observations from three instruments reveal the presence of a 4 M Jup planet candidate orbiting the K giant HD 76920. HD 76920b has an orbital eccentricity of 0.856 ± 0.009, making it the most eccentric planet known to orbit an evolved star. There is no indication that HD 76920 has an unseen binary companion, suggesting a scattering event rather than Kozai oscillations as a probable culprit for the observed eccentricity. The candidate planet currently approaches to about four stellar radii from its host star, and is predicted to be engulfed on a ~100 Myr timescale due to the combined effects of stellar evolution and tidal interactions.

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