How big is a binary star?

Answer 1

A binary star is a star system consisting of two stars orbiting around their common barycenter. Systems of two, three, four, or even more stars are called multiple star systems. These systems, especially when more distant, often appear to the unaided eye as a single point of light, and are then revealed as double (or more) by other means.

Answer 2

All types of binary stars.

Calculations of their orbits allow the masses of their component stars to be directly determined, which allows the radius and density, to be indirectly estimated.

Answer 3

Binary stars are actually very common; about half the stars - or something in that order - are part of a double or multiple star system. In other words, there are billions of binary stars in our galaxy alone.

Answer 4

No. A common point, not a common mass.

The point they both revolve around is the point between them where the pivot on the see-saw

would have to be in order for them to balance each other. If their masses are equal, then the point

is exactly mid-way between them.

If one body is much much more massive than the other one, then the point they both revolve

around may be so far off-center that it's actually inside the bigger one. That's the situation with

the earth and sun revolving around a common point, and also with the earth and moon revolving

around a common point.

Answer 5

Binary stars are stars in which two or more stars are in a system with each other. Generally, the two stars are orbiting around each other, each being influenced by the other´s gravity. Different types of stars can be in binary systems with each other, and most stars are in binary systems.

Answer 6

There are billions of binary stars in the Milky Way galaxy alone,
and no two of them are at exactly the same distance from us.
You've forgotten to mention which one you're interested in.

Answer 7

Two stars that are gravitationally bound - orbit each other.

Answer 8

A binary star is not a single entity. It is a pair of stars orbiting it's common centre of mass.

See related link for more information.

Answer 9

Lots of stars are binary or double.

Lots of stars are binary or double.

Lots of stars are binary or double.

Lots of stars are binary or double.

Answer 10

A binary star system is a system with two stars at the center. (think Tatooine.)

It's not a theory though, there was one discovered recently.