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arXiv · 1711.05378

The Pan-Pacific Planet Search VII: The most eccentric planet orbiting a giant star

Robert A. Wittenmyer·M. I. Jones·Jonathan Horner·Stephen R. Kane·J. P. Marshall·A. J. Mustill·J. S. Jenkins·P. A. Pena Rojas·Jinglin Zhao·Eva Villaver·R. P. Butler·Jake Clark
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Abstract

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$\pm$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 $\sim$100 Myr timescale due to the combined effects of stellar evolution and tidal interactions.

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Robert A. Wittenmyer, M. I. Jones, Jonathan Horner, Stephen R. Kane, J. P. Marshall, A. J. Mustill, J. S. Jenkins, P. A. Pena Rojas, Jinglin Zhao, Eva Villaver, R. P. Butler, Jake Clark. 2017-11-15. The Pan-Pacific Planet Search VII: The most eccentric planet orbiting a giant star. https://doi.org/10.3847/1538-3881%2Faa9894

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