The Aligned Orbit of the Eccentric Warm Jupiter K2-232b
Abstract
Measuring the obliquity distribution of stars hosting warm Jupiters may help us to understand the formation of close-orbiting gas giants. Few such measurements have been performed due to practical difficulties in scheduling observations of the relatively infrequent and long-duration transits of warm Jupiters. Here, we report a measurement of the Rossiter–McLaughlin effect for K2-232 b, a warm Jupiter on an 11.17 day orbit with an eccentricity of 0.26. The data were obtained with the Automated Planet Finder during two separate transits. The planet's orbit appears to be well aligned with the spin axis of the host star, with a projected spin–orbit angle of λ = −11.°1 ± 6.°6. Combined with the other available data, we find that high obliquities are almost exclusively associated with planets that either have an orbital separation greater than 10 stellar radii or orbit stars with effective temperatures hotter than 6000 K. This pattern suggests that the obliquities of the closest-orbiting giant planets around cooler stars have been damped by tidal effects.
Additional Information
© 2021. The American Astronomical Society. Received 2021 April 28; revised 2021 May 24; accepted 2021 May 26; published 2021 July 8. The authors thank Maximilian N. Güenther for helpful discussions on the Allesfitter and are also grateful to the anonymous referee for their constructive comments and suggestions. J.N.W. thanks the Heising-Simons Foundation for support. M.R. is supported by the National Science Foundation Graduate Research Fellowship Program under grant No. DGE-1752134. We are grateful to Metrics for providing helpful suggestions on the figure design. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). This work is supported by China National Astronomical Data Center (NADC), Chinese Virtual Observatory (China-VO), Astronomical Big Data Joint Research Center, and cofounded by National Astronomical Observatories, Chinese Academy of Sciences, and Alibaba Cloud.Attached Files
Published - Wang_2021_AJ_162_50.pdf
Submitted - 2105.12902.pdf
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Additional details
- Eprint ID
- 109942
- Resolver ID
- CaltechAUTHORS:20210720-221345357
- Heising-Simons Foundation
- DGE-1752134
- NSF Graduate Research Fellowship
- 80NM0018D0004
- NASA/JPL/Caltech
- Created
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2021-07-21Created from EPrint's datestamp field
- Updated
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2021-07-21Created from EPrint's last_modified field