astronomer vs Sir John Frederick William Herschel

astronomer and Sir John Frederick William Herschel both are nouns.

Word	Noun	Adjective	Verb	Adverb
astronomer	Yes	No	No	No
Sir John Frederick William Herschel	Yes	No	No	No

astronomer (noun)	Sir John Frederick William Herschel (noun)
a physicist who studies astronomy	English astronomer (son of William Herschel) who extended the catalogue of stars to the Southern Hemisphere and did pioneering work in photography (1792-1871)