astronomer vs uranologist

astronomer and uranologist both are nouns.

Word	Noun	Adjective	Verb	Adverb
astronomer	Yes	No	No	No
uranologist	Yes	No	No	No

As nouns, astronomer and uranologist are synonyms defined as:

Other synonyms of astronomer include stargazer.

astronomer (noun)	uranologist (noun)
a physicist who studies astronomy	a physicist who studies astronomy