a close binary that often cannot be separated, even with a telescope, but can be detected by changes in brightness caused by one component passing in front of the other, blocking out all, or some of its light
A binary system that is detected by the periodic eclipsing of each component star by the other. The resultant light curve shows primary eclipses when the dimmer star passes in front of the brighter star and a scondary eclipse or minimum when the brighter star eclipses the dimmer star. The component stars in an eclipsing binary are generally close to each other.
A system of two stars that periodically eclipse one another from our point of view on Earth. Astronomers cleverly use these observations to calculate mass, size, and distance. One noted eclipsing binary is called Algol, with a period of 2.87 days and a shift in magnitude of 1.2. See also
two stars orbiting each other in a plane that is along your line of sight so you see one star periodically pass in front of the other star. They are especially useful for determining the diameters and masses of stars.