New insights into how stars like the sun die might help explain why astronomers find bright planetary nebulae where they’re least expected. Simulations of how these stellar remnants form suggest that smaller stars have cores that heat up fast enough to produce bright nebulae upon their demise, researchers report online May 7 in Nature Astronomy.
A planetary nebula is what’s left over when a sunlike star sheds its outer envelope of gas. Radiation from the stellar core, now exposed, sets the expanding shell of gas aglow, creating the kind of candy-colored clouds seen in spectacular Hubble Space Telescope images, like that of the Cat’s Eye Nebula and the butterfly-shaped NGC 6302 (SN Online: 9/5/13).