What is heliocentric cosmology?
helio = sun centric = centered heliocentric cosmology = sun-centered cosmology as opposed to geocentric cosmology (geo=earth centric=centered, Earth centered cosmology) which has been outdated since Copernicus to restate: in heliocentric cosmology the planets rotate around the sun, as opposed to the much older geocentric cosmology where the planets and stars (including the sun) rotate around the Earth