Aristarchus of Samos (; Aristarkhos; c. 310 – c. 230 BC) was an ancient Greek astronomer and mathematician who presented the first known model that placed the Sun at the center of the known universe with the Earth revolving around it (see Solar system). He was influenced by Philolaus of Croton, but he identified the "central fire" with the Sun, and put the other planets in their correct order of distance around the Sun. As Anaxagoras before him, he suspected that the stars were just other bodies like the Sun. His astronomical ideas were often rejected in favor of the geocentric theories of Aristotle and Ptolemy.