The Dumbbell Nebula (also known as Messier 27, M 27, or NGC 6853) is a planetary nebula (PN) in the Vulpecula constellation, at a distance of about 1360 light years.

This object was the first planetary nebula to be discovered; by Charles Messier in 1764. At its brightness of visual magnitude 7.5 and its diameter of about 8 arcminutes, it is easily visible in binoculars, and a great observing target in amateur telescopes.

Structure

This PN appears to be shaped like an prolate spheroid and is viewed from our perspective along the plane of its equator. In 1992, Moreno-Corral et al. computed that the rate of expansion in the plane of the sky of this PN was no more than 2″.3 per century. From this, an upper limit to the age of 14,600 yr may be determined. In 1970, Bohuski, Smith, & Weedman found an expansion velocity of 31 km/s. Given the semi-minor axis radius of 1.11 ly, this implies that the kinematic age of the PN is 10,700 years old.

Knots

Like many nearby planetary nebulae, the Dumbbell contains knots. Its central region is marked by a pattern of dark and bright cusped knots and their associated dark tails (see picture). The knots vary in appearance from symmetric objects with tails to rather irregular tail-less objects. Similarly to the Helix Nebula and the Eskimo Nebula, the heads of the knots have bright cusps which are local photoionization fronts.

Central star

See also

• List of messier objects
• List of planetary nebulae
• New General Catalogue

Notes

References

External links

• SEDS Messier page on M27
• M27 Dumbbell Nebula
• M27 image taken by Stargazer Observatory
• M27