Milky Way System vs Milky Way

Milky Way System and Milky Way both are nouns.

Word	Noun	Adjective	Verb	Adverb
Milky Way System	Yes	No	No	No
Milky Way	Yes	No	No	No

As nouns, Milky Way System and Milky Way are synonyms defined as:

Milky Way System and Milky Way: the galaxy containing the solar system; consists of millions of stars that can be seen as a diffuse band of light stretching across the night sky

Other synonyms of Milky Way System include Milky Way Galaxy.

Milky Way System (noun)	Milky Way (noun)
the galaxy containing the solar system; consists of millions of stars that can be seen as a diffuse band of light stretching across the night sky	the galaxy containing the solar system; consists of millions of stars that can be seen as a diffuse band of light stretching across the night sky