M57 The Ring Nebula

The Ring Nebula is a planetary nebula about 2000 l.y away in the constellation Lyra. The Ring Nebula is also known as M57 or NGC 6720. The star in the middle, is very hot and is surrounded by a shell of luminous gas and dust, which is some three-quarters of a ligth year in diameter. The star is on itīs last years of itīs life and is blowing away itīs matter. In small telescopes, like mine, the shell looks like an elliptical smoke ring. The ring is expanding at 19 km/s. M57 can be located between the two naked-eye stars Beta and Gamma Lyrae. Itīs very hard to see with binoculars. This picture was imaged by the Hubble Space Telescope and itīs the sharpest view yet. The Hubble Space Telescope images reveal that the "Ring" is actually a cylinder of gas seen almost end on. Such elongation are common among other planetary nebula. The reason for that is the thick discs of gas and dust form a waist around dying star. This waist slows down the exspansion of material ejected by the doomed object. So the easiest escape route for this cast-off material is abowe and below the star. The green and red matter are oxygen and nitrogen ions. The blue color is hotter ionized helium. This new view was obtained October 16, 1998 by the Hubble Heritage Program team at the Space Telescope Science Institute in Baltimore, Maryland.

          M Number  NGC   Const   Mag     RA       dec       Type
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            M57     6720  Lyra    8,2  18h 53.6m  +33° 02ī  Planetary