Given a factoid/trivia type question, generate the topic of the question. The topic is the entity the question talks about.

Feb 15, 1564 saw the birth of what famed Italian physicist, mathematician, astronomer, and philosopher, who discovered the first 4 moons of Jupiter?
astronomer

'Highway 61 Revisited' and 'Blood On The Tracks' were both albums released by which popular singer?
highway 61 revisited

What breed of dog is Marmaduke in the newspaper cartoon strip of that name?

dog