Detached eclipsing binary star science in the 2040s
Pierre F. L. Maxted, Dominic M. Bowman, Thomas G. Wilson, Sophie Rosu, Keivan G. Stassun, Simon J. Murphy, Ayush Moharana, Amaury H. M. J. Triaud, Axel Hahlin, John Southworth
TL;DR
The paper argues that long-period detached eclipsing binaries (DEBS) are essential for calibrating stellar structure and evolution, but current DEBS samples are biased toward short periods. It outlines Open Science Questions for the 2040s, including how binarity, tides, and multiplicity affect evolution; constraints on interior mixing, rotation, and magnetic fields via asteroseismology and apsidal motion; and the role of magnetic fields in massive-star evolution and their connection to binary interaction. It then specifies required technology and data-handling capabilities to enable routine, high-precision spectroscopy of distant DEBS, emphasizing high-resolution spectrographs, flexible scheduling, stable RVs, rapid data products, and broad longitudinal coverage. The proposed facilities aim to extend precise mass-radius benchmarks to longer-period systems, improving tests of stellar evolution and informing exoplanet characterisation.
Abstract
Detached eclipsing binary stars (DEBS) are currently the best source of accurate and precise fundamental stellar parameters. This makes DEBS crucial targets for constraining the impact of various physical processes on stellar structure and evolution. Long-period binaries are particularly interesting because their separation minimises interactions between the components. This makes long-period binaries more comparable to single stars. However, the current sample of DEBS with high precision stellar parameters are dominated by short-period systems (e.g. ~90% of the Gaia DR3 eclipsing binaries have periods < 5 days). Facilities capable of performing detailed studies of long-period DEBS will be essential to further improve our understanding of stellar structure and evolution. Such facilities would need to be able to obtain spectroscopic observations of more distant objects at high resolution and cadence. 2-8m class telescopes with echelle spectrographs and an ability to monitor a large sample of stars would be required.