Discovered by Antoine Darquier de Pellepoix in 1779.
The famous Ring Nebula (M57) is often regarded as the prototype of a planetary nebula, and a showpiece in the Northern Hemisphere summer sky. Recent research has confirmed that M57 is, most probably, a ring (torus) of bright light-emitting material ejected from its central star. Our view of M57 is from a polar vantage point. We therefore are looking down the axis of a cylinder of ejected gas. The cylinder is thought to be much more complex than what one would think of as a tube or pipe. The nebula is most probably a bi-polar nebula consisting of two lobes emanating from a narrowed “waist”. The nebula consists of a very bright ring of gas and also a very faint “halo” of gas that was emitted during the central star’s red giant stage. The faint halo is usually visible only in long exposure images taken through a hydrogen alpha filter. The image above is a composite of “visible light” images and a hydrogen alpha image. The Ha image can be viewed here and better displays the faint outer halo of gases. Dr. Robert Gendler has a very good and detailed article describing this complex celestial object. A link to the article is below and is, in my opinion, one of the best descriptions of this wonderful celestial vista.