cosmologist vs uranologist

cosmologist and uranologist both are nouns.

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

As nouns, uranologist is a hypernym of cosmologist; that is, uranologist is a word with a broader meaning than cosmologist:

cosmologist: an astronomer who studies the evolution and space-time relations of the universe
uranologist: a physicist who studies astronomy

Other hypernyms of cosmologist include astronomer, stargazer.

cosmologist (noun)	uranologist (noun)
an astronomer who studies the evolution and space-time relations of the universe	a physicist who studies astronomy