M57

The Ring Nebula in the Constellation Lyra

The famous Ring Nebula (also catalogued as Messier 57, M57 or NGC 6720) appears in the northern constellation of Lyra.   It is a prominent example of a planetary nebula. This is a shell of ionized gas expelled into the surrounding interstellar medium by a red giant star, which was passing through the last stage in its evolution before becoming a white dwarf.  M57 is 2,300 light-years from Earth and has a diameter of 2.6 light-years.  Photographs taken over a period of 50 years show the rate of nebula expansion is roughly 20–30 km s.  M57 is illuminated by a central white dwarf.  M57 is an example of the class of planetary nebulae known as bipolar nebulae, whose thick equatorial rings visibly extend the structure through its main axis of symmetry.

Image Details:

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  • Instrument: Celestron C14 OTA @ f/6.3  (2208mm)
  • Mount: Celestron CGE GoTo
  • Image Scale:  0.7 arc-seconds/pixel
  • Filters: None
  • Exposure: 20 x 20 seconds
  • Camera: SBIG ST-2000XCM Color One-Shot with AO-7
  • Software: Maxim DL/CCD, Adobe Photoshop, RC Astro Gradient X-Terminator, Neat Image Pro
  • Location: Little Rock, AR., El. 350ft
  • Date: September 22, 2004