Two stars orbiting each other so that one regularly passes in front of the other blocking out some or all of light of the hidden star.
See related link for an animation.
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That's an 'eclipsing binary'.
An eclipsing binary star system. This occurs when one star passes in front of the other from the observer's perspective, causing periodic decreases in brightness as the light from the background star becomes blocked.
Yes. Zeta Tauri, Kappa Tauri, and Lambda Tauri are eclipsing binary stars.
That happens in an "eclipsing binary".
Each of those is an eclipsing binary.
Yes, because it is easier to determine the precise times of their mutual orbits, which allows us to calculate their masses.
Precisely by the eclipse - that's what an "eclipsing binary system" is all about. The idea is that one of the stars partially (or completely, in some cases) covers the other star; with the result that the combined brightness (as seen from Earth) gets less for some time.
Because in eclipsing binaries, the two stars orbit each other regularly passing in front of the other, blocking out some or all of light of the hidden star.
It is easy (with the right equipment ) to measure the periodicity of the eclipsing system and thereby the rotational speeds and thereby the relative masses and thereby (with the brightness) the distance and all sorts of other things.
Light curves of eclipsing binaries can provide information about the size and shape of the stars in the binary system, their temperatures, masses, and luminosities. By analyzing the periodic variation in the brightness of the system as one star passes in front of the other, astronomers can also determine the orbital period, inclination, and distance of the binary system.
An eclipsing binary system consists of two stars orbiting each other in such a way that they periodically pass in front of each other as seen from Earth. The light curve of an eclipsing binary system will show regular dips in brightness when one star crosses in front of the other, creating a characteristic pattern of alternating minima and maxima. These dips in brightness are caused by eclipses and can be used to determine various properties of the stars, such as their sizes and masses.