Exoplanets & Exomoons

The EBLM Project — From False Positives to Benchmark Stars and Circumbinary Exoplanet

By Keith Cowing
Status Report
November 30, 2023
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The EBLM Project — From False Positives to Benchmark Stars and Circumbinary Exoplanet
Phase-folded light curve of EBLM J0608βˆ’59 (TOI-1338, BEBOP-1) from the WASP project. The data in blue are phase-binned and offset vertically to make the transit at phase 0 easier to see in this automatically-generated diagnostic plot. This system was first flagged as an EBLM system by Amaury Triaud on 2010-07-02 based on follow-up radial velocity meausurements obtained with the CORALIE spectrograph on the Swiss Euler 1.2-m telescope. This binary would later be discovered to host two circumbinary planets, one identified from a transit observed in the TESS light curve [7] and the other long-period planet identified from radial-velocity measurements obtained by the BEBOP project [8]. — astro-ph.SR

The EBLM project aims to characterise very low-mass stars that are companions to solar-type stars in eclipsing binaries. We describe the history and motivation for this project, the methodology we use to obtain precise mass, radius and effective temperature estimates for very low-mass M-dwarfs, and review results of the EBLM study and those from related projects.

We show that radius inflation in fully-convective stars is a more subtle effect than was previously thought based on less precise measurements, i.e. the mass-radius-effective temperature relations we observe for fully-convective stars in single-line eclipsing binaries show reasonable agreement with theoretical models, particularly if we account for the M-dwarf metallicity, as inferred from the analysis of the primary star spectrum.

P. F. L. Maxted, A. H. M. J. Triaud, D. V. Martin

Comments: Accepted for publication in the journal Universe, special issue The Royal Road: Eclipsing Binaries and Transiting Exoplanets. 30 pages, 8 figures
Subjects: Solar and Stellar Astrophysics (astro-ph.SR); Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2311.16677 [astro-ph.SR] (or arXiv:2311.16677v1 [astro-ph.SR] for this version)
Submission history
From: Pierre Maxted
[v1] Tue, 28 Nov 2023 10:49:09 UTC (2,419 KB)

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) πŸ––πŸ»