Astronomy
The Classification of Planetary Nebulae and Their Central Stars
Quick fact
Despite their name, planetary nebulae have nothing to do with planets; they were named by William Herschel in the 1780s because their round shapes looked like planets through small telescopes.
Why this is interesting
You’ve probably seen images of glowing, colorful blobs in space—but did you know that what looks like a single object can be a whole system, and astronomers classify them by shape and by the star at their center?