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 by a gravitational bound collection of two or more stars. The first option describes an open cluster, the third refers to a stellar association, and the fourth is a specific type of binary star system, not the general definition of a star system.

Answer:

a group of two or more stars