It's pretty safe to say mankind has known about the Sun since, well, there was mankind. It's by far the brightest object in the sky, with an apparent magnitude of -26.7; that's about 400,000 times brighter than the Full Moon. It's also the biggest object in the local area by far — it makes up 99 percent of the material in the solar system. And, as anyone who's ever spent a long day outdoors knows, the Sun is almost incomprehensibly hot: Its surface temperature is about 9900° Fahrenheit (5500° Celsius).
Learn more about our hom star by registering with Astronomy.com and gaining access to the video, "Tour the solar system: The Sun."