Little Dumbbell Nebula

Barbell Nebula, Cork Nebula, M76, NGC 650/651

A planetary nebula in the far west of the constellation Perseus, close to the point where it meets Cassiopeia. In the sky, the Little Dumbbell lies approximately halfway between Perseus' Double Cluster and the Andromeda Galaxy, which lies relatively nearby to the south. At twelfth magnitude, however, it cannot be seen without optical aid (and indeed it is considered one of the faintest and most difficult of Messier's objects to detect).

Planetary nebulae are formed in supernovae, as the surviving outer layers of a red giant star that have been expelled out into space. The giant that formed the Little Dumbbell did not eject its matter in a completely regular manner, and the material ejected from the poles of the star went on to form two distinct arcing lobes to the nebula. The resulting doubled shape (and its general similarity to the Dumbbell Nebula in Vulpecula) give it the name 'Little Dumbbell'. Historically, its double-lobed appearance was thought to represent two distinct objects, and so the nebula is numbered twice in the New General Catalogue, as NGC 650 and NGC 651.

The matter of the Little Dumbbell is still expanding outwards from its parent star (the core of which is still faintly detectable in the heart of the nebula). This expansion is continuing at a rate approaching 40km per second, and the entire structure has now reached well over a light year in diameter.


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