page_title: NGC 6818
hierarchical_section_title: NGC 6818
caption_attribution_description: English: A en:Hubble Space Telescope (HST) image of en:NGC 6818 Credit: HST/en:NASA/en:ESA. http://www.spacetelescope.org/images/html/opo9811h.html
context_page_description: The Little Gem Nebula or NGC 6818 is a planetary nebula located in the constellation of Sagittarius. It has magnitude 10 and oval diameter of 15 to 22 arcseconds with a 15th magnitude central star.
  It was discovered by William Herschel in 1787.
  NGC 6818 is located in the constellation of Sagittarius, roughly 6000 light-years away from Earth. The glow of the cloud is just over half a light-year across.
  When stars like the Sun are near end of life, they send their outer layers into space to create glowing clouds of gas, a planetary nebulae. This ejection of mass is uneven, and planetary nebulae can have complex shapes. NGC 6818 shows knotty filament-like structures and distinct layers of material, with a bright and enclosed central bubble surrounded by a larger, more diffuse cloud.
  Scientists believe that the stellar wind from the central star propels the outflowing material, forming the elongated shape of NGC 6818. As this stellar wind moves through the slower-moving cloud it creates particularly bright spots in the bubble's outer layers.
context_section_description: The Little Gem Nebula or NGC 6818 is a planetary nebula located  in the constellation of Sagittarius. It has magnitude 10 and oval diameter of 15 to 22 arcseconds with a 15th magnitude central star.
  It was discovered by William Herschel in 1787.
  NGC 6818 is located in the constellation of Sagittarius (The Archer), roughly 6000 light-years away from Earth. The glow of the cloud is just over half a light-year across.
  When stars like the Sun are near end of life, they send their outer layers into space to create glowing clouds of gas, a planetary nebulae. This ejection of mass is uneven, and planetary nebulae can have complex shapes. NGC 6818 shows knotty filament-like structures and distinct layers of material, with a bright and enclosed central bubble surrounded by a larger, more diffuse cloud.
  Scientists believe that the stellar wind from the central star propels the outflowing material, forming the elongated shape of NGC 6818. As this stellar wind moves through the slower-moving cloud it creates particularly bright spots in the bubble's outer layers.
caption: A Hubble Space Telescope (HST) image of NGC 6818.
  Credit: HST/NASA/ESA.
exif: {"Image ImageDescription": "This Wide Field and Planetary Camera 2image of NGC 6818 shows two distinct layers of gas (with dust): a spherical outer region and a brighter, vase-shaped interior 'bubble.' Astronomers believe that a fast wind - material propelled by radiation from the hot central star - is creating the inner elongated shape. The central star of the planetary nebula appears as a tiny blue dot. The material in the wind is traveling so fast that it smashes through older, slower-moving stellar debris, causing a 'blowout' at both ends of the bubble (lower right and upper left)."}