Question

differentiating star systems
choose the word from the drop - down menu that completes each sentence
a/an blank star system is made of two stars.
a/an blank star system is made of no more than a few thousand stars.
a/an blank star system is made of more than a million stars.

Explanation:

A binary star system consists of two stars. A star - cluster (open cluster) typically has no more than a few thousand stars. A globular cluster is a star system with more than a million stars.

Answer:

1. Binary
2. Open - cluster
3. Globular - cluster