Some Information about the Sun Warning! You should never look directly at the Sun! Only look at the Sun with special telescopes and filters, or by projecting an image of the Sun on a screen.
The Sun is a star—the nearest star! See Figure 1
How big is the Sun? How much does it weigh?
Size: ~100 times as big across as Earth! (1.4 million km across)
Why does the Sun not collapse under its own weight?
Gravity wants to pullthe gas towards the center, but pressure from the hot gas wants to expand the Sun: these two forces balance. Imagine the Sun as a balloon.
Sunspots: these are places on the Sun that are cooler (by ~1500 deg) than the rest of the Sun, so they look darker (they’re still quite bright actually). See Figure 2
Prominences and filaments: dense, cold gas held above the Sun’s surface by the Sun’s magnetic field (you can think of the Sun like a big bar magnet). See Figure 3
Flares: Violent explosions that release lots of energy and particles from the Sun. See Figure 4.