eclipsing binary

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Related to Eclipsing binaries: Binary star system
Schematic of orbits and light curve of eclipsing binaryclick for a larger image
Schematic of orbits and light curve of eclipsing binary

eclipsing binary

A binary star whose orbital plane is orientated such that each component is totally or partly eclipsed by the other during each orbital period. The effect observed is a periodic decrease in the light from the system (see illustration). The deeper minimum corresponds to the eclipse of the brighter star. The light curve gives the period of revolution, and from the depths and shapes of the minima it is possible to estimate the inclination of the orbital plane. The duration of the eclipses compared to the time between eclipses indicates the radii of the stars in terms of the distance between them. If the system is also a double-lined spectroscopic binary the individual masses and radii of the stars can be calculated.

Eclipsing binaries tend to be composed of large stars with small orbits and therefore the majority are close binaries (see binary star). In these systems mass transfer affects the stars' evolution, leading to three main classes of eclipsing binaries. W Ursae Majoris stars are in contact. In W Serpentis stars one component is transferring mass rapidly to the other. In these two classes the stars are distorted into ellipsoids, an effect that shows in the light curve. Algol variables represent a later stage; mass transfer is almost complete and the stars are nearly spherical.

eclipsing binary

[i′klips·iŋ′bī‚nər·ē]
References in periodicals archive ?
Professional level measurements of eclipsing binaries are well within the reach of amateur astronomers.
PHOEBE, short for PHysics Of Eclipsing BinariEs, is a tightly integrated collection of software tools used to analyze observations of eclipsing binaries.
The All Sky Automatic Survey (ASAS) provides a database of over 5 000 eclipsing binaries stars, most of which have never been recognized before.
This is usually the case when observing eclipsing binaries.
The results for various eclipsing binaries are generally less precise than for WR20a, but they are all very encouraging: HD 15558 contains two objects of 152[+ or -]51 and 46[+ or -]11 solar masses; NGC 3603-A1 possesses two stars of 114[+ or -]30 and 84[+ or -]15 solar masses; WR25 consists of two stars of 75[+ or -]7 and 27[+ or -]3 solar masses; and R145 has two components of 140[+ or -]37 and 59[+ or -]26 solar masses.
As with many eclipsing binaries, the minima of SZ Her are slightly unpredictable.
Stars that vary for a completely different reason are eclipsing binaries, the best-known example being Algol ([beta] Persei).
The documentation has suggestions for using the program to illustrate the properties of eclipsing binaries and various exotic systems such as contact binaries, and interpreting their light and radial-velocity curves.
Parameters for eclipsing binaries can be imported from an Internet database, or you can create your own systems from scratch.
Sure enough, the eclipsing binaries listed here have periods of but a few days, indicating that they must be very tight pairs.
The A and B stars are eclipsing binaries with periods of 65 and 6.