track star vs sensation

track star and sensation both are nouns.

Word	Noun	Adjective	Verb	Adverb
track star	Yes	No	No	No
sensation	Yes	No	No	No

As nouns, sensation is a hypernym of track star; that is, sensation is a word with a broader meaning than track star:

Other hypernyms of track star include ace, adept, champion, genius, hotshot, maven, mavin, star, superstar, virtuoso, whiz, whizz, wiz, wizard.

track star (noun)	sensation (noun)
a star runner	an unelaborated elementary awareness of stimulation
	the faculty through which the external world is apprehended
	a general feeling of excitement and heightened interest
	someone who is dazzlingly skilled in any field
	a state of widespread public excitement and interest