aurora australis vs aurora

aurora australis and aurora both are nouns.

Word	Noun	Adjective	Verb	Adverb
aurora australis	Yes	No	No	No
aurora	Yes	No	No	No

As nouns, aurora is a hypernym of aurora australis; that is, aurora is a word with a broader meaning than aurora australis:

aurora australis: the aurora of the Southern Hemisphere
aurora: an atmospheric phenomenon consisting of bands of light caused by charged solar particles following the earth's magnetic lines of force

aurora australis (noun)	aurora (noun)
the aurora of the Southern Hemisphere	an atmospheric phenomenon consisting of bands of light caused by charged solar particles following the earth's magnetic lines of force
	the first light of day