M57: The Ring Nebula

Click on image for larger version.

The ring nebula is probably one of the most famous deep sky objects in the sky. Generally when amatuers begin their telescopic journey, after the Orion Nebula , the Ring is one of the next objects on the list. Even through a small telescope its bright and distinctive shape sets it apart from a typical field of stars. An image such as this, when acquired using a CCD camera, shows both the detail and color of this remarkable object. Like others of its type, the Ring Nebula is the expelled outer envelope of a once aged star that has now reached its final stages of life. This bubble of gas is more than 2,000 light years away and therefore is itself more than 1 light year in diameter. The white dwarf (central star which is the naked core of the original sunlike whole) is extremely hot (100,000K) and emits copious amounts of UV radiation. This emission excites various gases in the bubble and makes them glow (not unlike a neon light). The sphere of gas continues to expand; and if we could watch for the next 300,000 years the bubble would thin and disintegrate leaving the cold dark husk of the cooled white dwarf.

Technically a better description of this "bubble" of gas is something a bit more cylindrical. In this case we are looking down the major axis (shaft) of the short tube. Previous episodes of mass loss can be seen in concentric layers far from the brightest portion. The bottom image attempts to display these features. Please visit the NOAO M57 to see a similar picture created with a larger telescope. If we were able to look at the ring nebula from the side (rotate 90 degrees), it would look like M76. Also note the galaxy, IC 1296, which floats majestically in the background.

(For the top image)


20in RC Optical Systems telescope Operating at f/8.4
Paramount ME Robotic Telescope Mount
SBIG ST10XME CCD camera with color filter wheel

L R G B color production was used to create this image.

Luminance = 85 minutes binned 1x1
Red = 30 minutes binned 2x2
Green = 30 minutes binned 2x2
Blue = 30 minutes binned 2x2

  • Both top and bottom images were created from the same data set.
  • The bottom image (showing the extended envelope) was agreessively smoothed in order to minimize the granular appearence.
  • This data set is the combination of two separate imaging sessions. The first session was with Jim Quinn (a reporter for the Arizona Highways and the second session was with Steve Mandel.
  • Eight iterations of L-R deconvolution (sharpening) algorithm using CCDsharp were applied to resampled (double) luminance image.

  • Minimum credit line: Adam Block/NOAO/AURA/NSF (top)

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    Updated: 05/2003