, 1 min, 144 words
Tags: physics astrophysics
Rather than a general physics fact, I thought it'd be fun to share a few facts about a star familiar to many stargazers: Betelgeuse, the left shoulder of Orion (you know, the guy with the belt). If it were in our solar system centered at the Sun, its boundary would extend well past the orbit of Mars - that's one big star. It's a supergiant, which means that its surface is cooler than smaller stars like the sun. So it appears noticeably red, even for stargazers in the light-pollution capital of the world, Los Angeles.
To complicate matters, it seems that Betelgeuse also grows and shrinks periodically, and experiences corresponding changes in brightness and color. And all of this is hard to see, because it's surrounded by a very strangely-shaped cloud (remember the interstellar medium?), which interferes with observations. Experimentalists are really impressive!