What is the difference between an optical double star and a visual binary star?
A) An optical double is an illusion-the stars are at vast distances from each other and are not actually orbiting each other-whereas in a visual binary, the stars are actually orbiting each other.
B) There is no difference; they are two names for the same thing.
C) The stars in an optical double star are actually orbiting each other, whereas a visual binary is an illusion. The stars are at vast distances from each other and are not actually orbiting each other.
D) Optical double stars can be seen as separate stars only through a telescope, whereas visual binaries can be seen with the unaided eye (e.g., the star Mizar in the Big Dipper's handle).

Question

Quizplus · Accepted Answer

An optical double star appears to be close together when viewed from Earth, but the stars are not gravitationally bound and are at significantly different distances from us. In contrast, a visual binary consists of two stars that are gravitationally bound and orbit each other, which can sometimes be resolved as separate stars through a telescope or, in rare cases, with the naked eye.

What Is the Difference Between an Optical Double Star and a Visual