Wide binaries (EA)¶
Wide binaries (Algol variables) comprise two stars that are so far separated that the light curve varies little outside of the eclipses. The eclipses allow us to measure the inclination of the orbital axis relative to our line of sight so, combined with spectroscopic measurements of the stars’ radial velocities, allow one to determine the masses and radii of the stars with very few assumptions. These stars have been and still are invaluable for testing our understanding of stellar physics.
Stars can be quite small and there are eclipsing binaries with short periods that are nevertheless “wide” in the sense that the stars are well separated. There are also systems with very long orbits, which are generally not easy to find with TESS because its observing strategy, which operates in (partially overlapping) segments of about 27.4 days, but there are striking exceptions.