Questions About Nebulae
Most recent answer: 01/15/2017
- Paige (age 11)
1. Three of the most famous nebulae are the Orion Nebula, the Crab Nebula, and the Cat's Eye Nebula. Nebula is a general word for a cloud of dust and gases in space, and these three nebulae were actually all created in different ways (see next answer!)
2. The Orion Nebula is a cloud of dust, held together by gravity, which is collapsing in some places to form new stars. The high-energy light from the nearby stars makes the dust and gas glow. You can actually see the Orion Nebula with your naked eye on a dark night, and it's very impressive through binoculars. Look for a fuzzy region around the middle star of Orion's "sword" (which is hanging down from his "belt").
The Crab Nebula, on the other hand, was made by a dying star. The star exploded in a supernova in 1054 AD (which we know because ancient astronomers actually saw it). Only the most massive stars explode this way. The nebula is made up of glowing gases in the shock wave of the supernova, still expanding almost 1,000 years later.
The Cat's Eye Nebula was created by a different kind of dying star. This star wasn't massive enough to explode as a supernova, but instead it's slowly expanding, losing its outer layers of gases, and getting brighter. The nebula is made of this expanding cloud of lost gas, which glows in the intense light of the star.
3. Some nebulae are named for the constellation they're found in, like the Orion Nebula and the Carina Nebula. Others are named for what the first people to observe them thought they looked like.
4. William Parsons, an Irish astronomer, made a drawing of the nebula in 1844 and thought it looked like a crab. He later changed his mind, but the name stuck (as names often do).
(published on 01/15/2017)