binary star

American  

noun

Astronomy.

1. a system of two stars that revolve about their common center of mass.

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binary star British  

noun

1. Sometimes shortened to: binary.  a double star system comprising two stars orbiting around their common centre of mass. A visual binary can be seen through a telescope. A spectroscopic binary can only be observed by the spectroscopic Doppler shift as each star moves towards or away from the earth See also optical double star eclipsing binary

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binary star Scientific  

1. A system of two stars that orbit a common center of mass, appearing as a single star when visible to the unaided eye. The orbital periods of binary stars range from several hours to several centuries. By some estimates, at least half of the stars in the Milky Way galaxy are members of binary star systems.

2. Also called double star

3. ◆ Binary stars are divided into four main classes based on how their dual nature is detected. A visual binary can be resolved telescopically into its two components. Only one star of an astrometric binary is visible, but the unseen component can be identified from its gravitational effect on the visible star, causing it to oscillate slightly, or wobble, against the background of more distant stars. The two components of a spectroscopic binary are identified based on their varying orbital velocities toward or away from Earth as revealed by periodic Doppler shifts in their spectral lines. In an eclipsing binary, the two components orbit each other in such a way that they periodically obscure or eclipse each other as viewed from Earth, causing changes in their observed brightness. Eclipsing binaries are also considered a kind of variable star.

4. ◆ Two stars that lie very close to each other along an observer's line of sight but that are not associated with each other in a gravitational system are known as optical binaries. Although they appear close to each other in the sky, such stars are actually very distant from each other in space.

5. See also multiple star variable star

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Etymology

Origin of binary star

First recorded in 1875–80

Example Sentences

The researchers explained that the precise physical interactions that occur during the merger can impact the types of signals that could be observed on Earth from binary star mergers.

From Science Daily

Their study of an unusual binary star system has resulted in convincing evidence that massive stars can completely collapse and become black holes without a supernova explosion.

From Science Daily

Previous studies have proposed three possible explanations for observed chemical differences between binary stars.

From Science Daily

According to the study's authors, there are more climate-friendly planets in binary star systems -- in other words, those with two suns -- than previously known.

From Science Daily

It was just like when a binary star—two stars going around the same point—grows farther apart.

From Literature