NGC 6888 (The Crescent Nebula)

 NGC 6888 is located approximately 4,700 light years from earth and is known as the Crescent Nebula because of its distinctive shape.  Technically it is classified as a Wolf-Rayet nebula.  Such a nebula is formed when a very hot, massive star ejects its outer layers in a strong stellar wind.  In the case of the Crescent Nebula the star responsible (WR 136) is the bright star in the center of the image above.  As the star ages it begins to shrink and grow much hotter.  Its stellar wind becomes more rarefied but much faster.  This fast stellar wind then collides with the older ejected gas and pushes it into a relative dense bubble.  The radiation from the hot central star excites the gas, principally hydrogen, causing it to shine in the red spectrum typical of an emission nebula.  The image above was captured using a hydrogen alpha filter. This filter is deep red in color and aids in bringing out fine detail of the nebula.  WR 136 is in the final stages of its stellar life and is estimated to explode in a supernova event within the next million years

Sharpless 2-112 ( The Clown Face Nebula)

Sharpless 2-112 is a bright emission nebula in Cygnus, just west of the brilliant star Deneb. It lies about 5,500 light years distant and spans 25 light years in size. This nebula is also known as the Clown Nebula or Clown Face Nebula. If one looks close enough, you can see a pair of eyes, nose, and a mouth with a tongue sticking out, along with some stringy hair.

NGC 281 ( The Pac-Man Nebula )

Is an H2 region in the constellation of Cassiopeia and part of the Perseus spiral arm. It includes or is near the open cluster IC 1590, the double star HD 5005. It is visible in amateur telescopes from dark sky locations. It is sometimes referred to as the Pacman Nebula owing to its resemblance to the eponymous hero of the arcade game Pac-Man.

This page last updated 10-26-09