Question

what phrase best defines a star system?
a group of hundreds of stars
a group of two or more stars
a group of stars that formed around the same time
a group of two stars in which one star is brighter than the other

Explanation:

A star system is defined as a group of two or more stars that are gravitationally bound to each other. The first option “a group of hundreds of stars” is too vague and not the standard definition. The third option “a group of stars that formed around the same time” is not the key defining characteristic. The fourth option “a group of two stars in which one star is brighter than the other” is too narrow as it only focuses on a property (brightness) of a two - star system, not the general definition.

Answer:

a group of two or more stars