Messier 27 The Dumbbell Nebula
Distance: 1,360 Light Years
Size: 8 x 5.7 Arc-minutes
Age: 3,000-48,000 Years
Telescope: Takahashi TOA-130
Camera: QSI 683
Mount: AP 900
Exposures: Ha 20×1200 Bin 1, OIII20x1200 Bin 1
Messier 27 is a large planetary nebula in the constellation Vulpecula. At a size of 4.5 light years across it is a little wider than the distance from our sun to our nearest star. M27 was the first Planetary nebula discovered in 1764 and since then nearly 3000 have been cataloged. The central star of M27 is in the process of dying and as a result has lost most of its outer layers to the stellar medium. What is left is a dwarf star that is very hot and illuminating the ejected gas as it is moving away from the area. Measurements of the expansion rate of the outer layers varies, some have a rate as large as 6.8 arc second per century while others show 1 arc seconds per century. This difference effects the estimated age of the nebula, from as young as 3,000 years to as old as 48,000 years.
Planetary nebula are formed from stars with solar masses of 1-8 times that of our sun. This is really a dying star that is too small to go supernova. Its death spiral begins with a shedding of outer layers that are ejected from the surface. This shedding of gas is the result of gravity overpowering the internal pressure created by fusion. As the star exhausts its hydrogen it is forced to use other elements until this higher pressure can no longer be maintained. At this point the star begins to shed its outer layers while the remaining layers start to collapse causing the core to heat up. The central star can have a surface temperature of 20,000K to 250,000K and it is this extreme ultraviolet radiation that ejects the outer layers, shapes them, and illuminates them.
Planetary nebula are great objects for studying how stars such as own will end. In addition, the ejected gasses can be studied for their chemical composition. Furthermore, elements in the gasses are now available for use by the galaxy in future star or planetary formation.
This image was captured from my house in a Bortle 6 zone.