Dumbbell Nebula is a nebula that looks like a dumbbell in the constellation Vulpecula, at a distance of about 1,360 light years. This gas cloud spreads over a distance of 4.5 light-years of space.
This nebula can be spotted with a regular set of binoculars. It was the first planetary nebula to be discovered by Charles Messier, in 1764. Hence, it has a relatively low number in the Messier catalogue, M27.
The expansion velocity of this cloud was calculated to be 31km/s.
Its central region consists of patterns of dark and bright cusped knots. Some knots look like symmetric knots with tails, some like irregular tail-less objects.
The center is believed to contain a large white dwarf star.
Sources:
http://en.wikipedia.org/wiki/File:M27_MRussell.jpg
http://en.wikipedia.org/wiki/Dumbbell_Nebula
http://messier.seds.org/more/m027_more.html dumbbell close-up image
http://www.nasa.gov/mission_pages/spitzer/multimedia/pia14417.html
Image source: NASA