Ring Nebula

Lore & Background

Charles Messier came across the nebula in late January 1779 while hunting for comets, and it became the 57th entry in his catalogue. Antoine Darquier de Pellepoix found it independently soon afterwards while tracking Comet Bode, describing it as a fading, planet-like disk about the size of Jupiter, a description that may have helped the term planetary nebula stick. Messier and William Herschel suspected it was a cluster of faint stars their telescopes could not separate.

In 1800 Friedrich von Hahn reported spotting the faint central star. William Huggins studied its spectrum in 1864 and found bright emission lines typical of glowing gas, showing that such nebulae were not unresolved stars. Eugene von Gothard photographed it in 1886 and identified the central star on September 1 of that year.

Reader's Guide

To find M57, look south of Vega, about 40% of the way from Beta to Gamma Lyrae. Binoculars cannot resolve it, but a 7.5 cm telescope shows its oval ring and a 10 cm scope at 100× reveals the dark centre; UHC or OIII filters help under city skies.

The blue-green interior comes from doubly ionized oxygen, while the reddish outer edge shows hydrogen and ionized nitrogen emission. The nebula is probably a prolate spheroid seen at about 30° to its axis and has been expanding for around 1,610 years. Its central star, near magnitude 15.75, is hard to see.

Did You Know?

• The central star shines about 300 times more brightly than the Sun.
• In 2025 JWST detected a dust disk around the central star.
• Photographs spanning 50 years show the nebula growing by roughly 1 arcsecond per century.
• The spiral galaxy IC 1296 appears near it in deep images.