Calabash Nebula

The Calabash Nebula, also known as the Rotten Egg Nebula or by its technical name OH 231.84 +4.22, is a protoplanetary nebula long and located some from Earth in the constellation Puppis. The name "Calabash Nebula" was first proposed in 1989 in an early paper on its expected nebular dynamics, based on the nebula's appearance.
The Calabash is almost certainly a member of the open cluster Messier 46, as it has the same distance, radial velocity, and proper motion. The central star is QX Puppis, a binary composed of a very cool Mira variable and an A-type main-sequence star.

Ground-based imagery

In wide field images, the Calabash nebula is visible near the bright planetary nebula NGC 2438 in deep photographs. Although the Calabash Nebula is at the same distance as M46, NGC 2438 is a larger object in the foreground.