Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA); Acknowledgment: R. Sahai and J. Trauger (Jet Propulsion Laboratory)

This planetary nebula is known as Kohoutek 4-55 (or K 4-55). A planetary nebula contains the outer layers of a red giant star that were expelled into interstellar space when the star was in the late stages of its life. Ultraviolet radiation emitted from the remaining hot core of the star ionizes the ejected gas shells, causing them to glow. In the specific case of K 4-55, a bright inner ring is surrounded by a bipolar structure. The entire system is then surrounded by a faint red halo, seen in the emission by nitrogen gas. This multi-shell structure is fairly uncommon in planetary nebulae. K 4-55 is nearly 4,600 light-years away in the constellation Cygnus.

Provider: Space Telescope Science Institute

Image Source: https://hubblesite.org/contents/news-releases/2009/news-2009-21

Curator: STScI, Baltimore, MD, USA

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