Which of these is not a type of true binary system, or, in other words, that the stars are NOT physically associated with each other?
A) optical double
B) visual binary
C) spectroscopic binary
D) eclipsing binary

Question

Quizplus · Accepted Answer

Optical doubles are pairs of stars that appear close to each other in the sky as seen from Earth but are not gravitationally bound and can be at vastly different distances from us. This contrasts with visual, spectroscopic, and eclipsing binaries, which are types of true binary systems where the stars are physically associated and orbit a common center of mass.

Which of These Is Not a Type of True Binary