apex vs solar apex

apex and solar apex both are nouns.

Word	Noun	Adjective	Verb	Adverb
apex	Yes	No	No	No
solar apex	Yes	No	No	No

As nouns, apex and solar apex are synonyms defined as:

apex and solar apex: the point on the celestial sphere toward which the sun and solar system appear to be moving relative to the fixed stars

Other synonyms of apex include apex of the sun's way.

apex (noun)	solar apex (noun)
the highest point (of something)	the point on the celestial sphere toward which the sun and solar system appear to be moving relative to the fixed stars
the point on the celestial sphere toward which the sun and solar system appear to be moving relative to the fixed stars