According to the heliocentric model of the solar system, what is at the center?

The heliocentric model of the solar system, developed by Copernicus in the 16th century, posits that the Sun is at the center of the solar system, with the planets, including Earth, orbiting around it. This model marked a significant shift from the earlier geocentric model, which incorrectly placed the Earth at the center. The heliocentric concept explains the observed movements of celestial bodies more accurately, as it aligns with the law of gravitation proposed by Newton, demonstrating how the gravitational pull of the Sun influences the orbits of the planets.

In this context, the Sun's position at the center is crucial for the understanding of planetary motion, seasons, and the cycle of day and night, all of which are tied to the relative positions and movements of these celestial bodies within the solar system.