The Sun wasn't "discovered" in a specific year like a new planet or star. Humans have always been aware of the Sun. It's been a fundamental part of our lives and understanding of the world since the beginning of our existence.

Here's why:

* The Sun is essential for life: We depend on the Sun for warmth, light, and the energy that fuels plant growth.

* Ancient civilizations worshipped the Sun: Many cultures throughout history have recognized the Sun's importance and deified it.

* Early astronomers studied the Sun: While they didn't have modern telescopes, they observed the Sun's movement and its influence on Earth's seasons.

So, instead of a specific year, we can say our understanding of the Sun has evolved over centuries, with advancements in astronomy leading to a deeper knowledge of its composition, behavior, and its role in our solar system.