- Stars are of many sizes, from red dwarfs, about 10 times larger than the planet Jupiter to super giants that are over a hundred times larger than our sun, which is a small yellowish star. Most stars are red dwarfs, however they are so dim that few can be seen by the naked eye or even by using telescopes on the ground. Many more have been photographed by using orbiting space telescopes.
- The larger a star is, the shorter it exists. Our sun has been around for about five billion years and will remain for roughly another five billion. Red dwarf stars might be around for several hundred billion years or even more. Super giant stars, on the other hand, can have an existence of a few hundred thousand years.
- No star has ever been discovered that doesn't spin.
- As many as 2/3 of all stars are found in groups of two or more, meaning that two or more stars revolve around each other.
- Our sun doesn't belong to such a group, but the nearest star to the sun, Proxima Centauri, does. Proxima is so dim compared to the other stars in the group that it is difficult to make out. Though it is the closest star to our own, that star is still so far away that it takes light from Proxima a bit over four years to reach us. Put in another way, Proxima is about 25,000,000,000,000 miles away.
- The earth is roughly 8 light minutes from the sun, meaning that if the sun suddenly went dark, we wouldn't know it, visually, for 8 minutes.
- Sunspots are magnetic storms on the sun. They are actually extremely bright and only look dark because the surrounding part of the sun is many times brighter still.
- Even small stars like our sun are enormous. In our own solar system, counting all the planets, moons, asteroids, comets and dust, the sun still accounts for over 99.8% of the mass in the solar system.
- As far away as the nearest stars are, our nighttime appears dark. If our sun was near the center of our galaxy, where stars are much closer together, a person could easily read a newspaper by starlight in the middle of the night, assuming that they could somehow exist.