Coel Hellier c.hellier@keele.ac.uk
The EBLM project. VII. Spin–orbit alignment for the circumbinary planet host EBLM J0608-59 A/TOI-1338 A
Hellier; Maxted
Abstract
A dozen short-period detached binaries are known to host transiting circumbinary planets. In all circumbinary systems so far, the planetary and binary orbits are aligned within a couple of degrees. However, the obliquity of the primary star, which is an important tracer of their formation, evolution, and tidal history, has only been measured in one circumbinary system until now. EBLM J0608-59/TOI-1338 is a low-mass eclipsing binary system with a recently discovered circumbinary planet identified by TESS. Here, we perform high-resolution spectroscopy during primary eclipse to measure the projected stellar obliquity of the primary component. The obliquity is low, and thus the primary star is aligned with the binary and planetary orbits with a projected spin–orbit angle ß = 2?.8 ± 17?.1. The rotation period of 18.1 ± 1.6 d implied by our measurement of vsin i? suggests that the primary has not yet pseudo-synchronized with the binary orbit, but is consistent with gyrochronology and weak tidal interaction with the binary companion. Our result, combined with the known coplanarity of the binary and planet orbits, is suggestive of formation from a single disc. Finally, we considered whether the spectrum of the faint secondary star could affect our measurements. We show through simulations that the effect is negligible for our system, but can lead to strong biases in vsin i? and ß for higher flux ratios. We encourage future studies in eclipse spectroscopy test the assumption of a dark secondary for flux ratios ?1ppt.
Acceptance Date | Jul 13, 2020 |
---|---|
Publication Date | Sep 1, 2020 |
Publicly Available Date | Mar 28, 2024 |
Journal | Monthly Notices of the Royal Astronomical Society |
Print ISSN | 0035-8711 |
Publisher | Oxford University Press |
Pages | 1627-1633 |
DOI | https://doi.org/10.1093/mnras/staa2071 |
Keywords | binaries: eclipsing – stars: low-mass – stars: individual (EBLM J0608-59, TOI-1338) – planets and satellites: formation – stars: rotation |
Publisher URL | https://academic.oup.com/mnras/article/497/2/1627/5871829 |
Files
staa2071.pdf
(909 Kb)
PDF
You might also like
A Mini-Neptune Orbiting the Metal-poor K Dwarf BD+29 2654
(2023)
Journal Article
Radial-velocity discovery of a second planet in the TOI-1338/BEBOP-1 circumbinary system
(2023)
Journal Article
The TESS Grand Unified Hot Jupiter Survey. II. Twenty New Giant Planets*
(2023)
Journal Article
TOI-4562b: A Highly Eccentric Temperate Jupiter Analog Orbiting a Young Field Star
(2023)
Journal Article
TOI-969: a late-K dwarf with a hot mini-Neptune in the desert and an eccentric cold Jupiter
(2023)
Journal Article
Downloadable Citations
About Keele Repository
Administrator e-mail: research.openaccess@keele.ac.uk
This application uses the following open-source libraries:
SheetJS Community Edition
Apache License Version 2.0 (http://www.apache.org/licenses/)
PDF.js
Apache License Version 2.0 (http://www.apache.org/licenses/)
Font Awesome
SIL OFL 1.1 (http://scripts.sil.org/OFL)
MIT License (http://opensource.org/licenses/mit-license.html)
CC BY 3.0 ( http://creativecommons.org/licenses/by/3.0/)
Powered by Worktribe © 2024
Advanced Search