Who was known for the pioneer theories about heliocentrism?

The pioneer theories about heliocentrism are most famously associated with Nicolaus Copernicus, a 16th-century astronomer who proposed that the Earth and other planets revolve around the Sun. His landmark work, "De revolutionibus orbium coelestium," published in 1543, challenged the long-held geocentric model that placed the Earth at the center of the universe. Copernicus's ideas laid the groundwork for future astronomers, including Galileo Galilei and Johannes Kepler, who further developed and supported the heliocentric theory.