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Comets Kick up Dust in Helix
…
| Title |
Comets Kick up Dust in Helix Nebula |
| Description |
This infrared image from NASA's Spitzer Space Telescope shows the Helix nebula, a cosmic starlet often photographed by amateur astronomers for its vivid colors and eerie resemblance to a giant eye. The nebula, located about 700 light-years away in the constellation Aquarius, belongs to a class of objects called planetary nebulae. Discovered in the 18th century, these colorful beauties were named for their resemblance to gas-giant planets like Jupiter. Planetary nebulae are the remains of stars that once looked a lot like our sun. When sun-like stars die, they puff out their outer gaseous layers. These layers are heated by the hot core of the dead star, called a white dwarf, and shine with infrared and visible colors. Our own sun will blossom into a planetary nebula when it dies in about five billion years. In Spitzer's infrared view of the Helix nebula, the eye looks more like that of a green monster's. Infrared light from the outer gaseous layers is represented in blues and greens. The white dwarf is visible as a tiny white dot in the center of the picture. The red color in the middle of the eye denotes the final layers of gas blown out when the star died. The brighter red circle in the very center is the glow of a dusty disk circling the white dwarf (the disk itself is too small to be resolved). This dust, discovered by Spitzer's infrared heat-seeking vision, was most likely kicked up by comets that survived the death of their star. Before the star died, its comets and possibly planets would have orbited the star in an orderly fashion. But when the star blew off its outer layers, the icy bodies and outer planets would have been tossed about and into each other, resulting in an ongoing cosmic dust storm. Any inner planets in the system would have burned up or been swallowed as their dying star expanded. So far, the Helix nebula is one of only a few dead-star systems in which evidence for comet survivors has been found. This image is made up of data from Spitzer's infrared array camera and multiband imaging photometer. Blue shows infrared light of 3.6 to 4.5 microns, green shows infrared light of 5.8 to 8 microns, and red shows infrared light of 24 microns. |
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Comets Kick up Dust in Helix
…
| Title |
Comets Kick up Dust in Helix Nebula |
| Description |
This infrared image from NASA's Spitzer Space Telescope shows the Helix nebula, a cosmic starlet often photographed by amateur astronomers for its vivid colors and eerie resemblance to a giant eye. The nebula, located about 700 light-years away in the constellation Aquarius, belongs to a class of objects called planetary nebulae. Discovered in the 18th century, these colorful beauties were named for their resemblance to gas-giant planets like Jupiter. Planetary nebulae are the remains of stars that once looked a lot like our sun. When sun-like stars die, they puff out their outer gaseous layers. These layers are heated by the hot core of the dead star, called a white dwarf, and shine with infrared and visible colors. Our own sun will blossom into a planetary nebula when it dies in about five billion years. In Spitzer's infrared view of the Helix nebula, the eye looks more like that of a green monster's. Infrared light from the outer gaseous layers is represented in blues and greens. The white dwarf is visible as a tiny white dot in the center of the picture. The red color in the middle of the eye denotes the final layers of gas blown out when the star died. The brighter red circle in the very center is the glow of a dusty disk circling the white dwarf (the disk itself is too small to be resolved). This dust, discovered by Spitzer's infrared heat-seeking vision, was most likely kicked up by comets that survived the death of their star. Before the star died, its comets and possibly planets would have orbited the star in an orderly fashion. But when the star blew off its outer layers, the icy bodies and outer planets would have been tossed about and into each other, resulting in an ongoing cosmic dust storm. Any inner planets in the system would have burned up or been swallowed as their dying star expanded. So far, the Helix nebula is one of only a few dead-star systems in which evidence for comet survivors has been found. This image is made up of data from Spitzer's infrared array camera and multiband imaging photometer. Blue shows infrared light of 3.6 to 4.5 microns, green shows infrared light of 5.8 to 8 microns, and red shows infrared light of 24 microns. |
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M27: The Dumbbell Nebula
| Title |
M27: The Dumbbell Nebula |
| Explanation |
The first hint of what will become of our Sun [ http://www.nineplanets.org/sol.html ] was discovered inadvertently in 1764. At that time, Charles Messier [ http://www.seds.org/messier/xtra/history/biograph.html ] was compiling a list of "annoying" diffuse objects not to be confused with "interesting" comets. The 27th object on Messier's list [ http://antwrp.gsfc.nasa.gov/apod/ap960626.html ], now known as M27 [ http://www.seds.org/messier/m/m027.html ] or the Dumbbell Nebula, is a planetary nebula [ http://antwrp.gsfc.nasa.gov/apod/planetary_nebulae.html ], the type of nebula our Sun [ http://antwrp.gsfc.nasa.gov/apod/sun.html ] will produce when nuclear fusion [ http://fusedweb.pppl.gov/ ] stops in its core. M27 [ http://antwrp.gsfc.nasa.gov/apod/ap981009.html ] is one of the brightest planetary nebulae [ http://www.seds.org/messier/planetar.html ] on the sky, and can be seen in the constellation [ http://www.att.virtualclassroom.org/vc99/vc_04/cons_stars/cons/hist_cons.html ] Vulpecula [ http://www.astronomical.org/constellations/vul.html ] with binoculars. It takes light about 1000 years to reach us from M27, shown above [ http://www.noao.edu/image_gallery/html/im0589.html ] in representative colors. Understanding the physics and significance of M27 [ http://www.seds.org/messier/twn/n6853x.html ] was well beyond 18th century science. Even today, many things remain mysterious about bipolar planetary nebula [ http://antwrp.gsfc.nasa.gov/apod/ap001217.html ] like M27, including the physical mechanism that expels a low-mass star's gaseous outer-envelope, leaving an X-ray [ http://www.treasure-troves.com/physics/X-Ray.html ] hot white dwarf [ http://www.sciencenet.org.uk/database/Physics/Stars/p01158c.html ]. |
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NGC 6369: The Little Ghost N
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| Title |
NGC 6369: The Little Ghost Nebula |
| Explanation |
This pretty planetary nebula, cataloged as NGC 6369 [ http://rao.150m.com/NGC6369.html ], was discovered by 18th century astronomer William Herschel [ http://www.bath-preservation-trust.org.uk/museums/ herschel/ ] as he used a telescope to explore the constellation Ophiucus [ http://www.corona_borealis.homestead.com/files/ pronouncing_the_stars.htm ]. Round and planet-shaped, the nebula is also relatively faint [ http://astro.isi.edu/reference/herschel.html ] and has acquired the popular moniker of Little Ghost Nebula. Planetary nebulae [ http://www.seds.org/messier/planetar.html ] in general are not [ http://antwrp.gsfc.nasa.gov/apod/ap020302.html ] at all related to planets, but instead are created at the end of a sun-like star's life as its outer layers expand [ http://antwrp.gsfc.nasa.gov/apod/ap010805.html ] into space while the star's core shrinks to become a white dwarf. The transformed white dwarf star [ http://antwrp.gsfc.nasa.gov/apod/ap000910.html ], seen near the center, radiates strongly at ultraviolet wavelengths and powers the expanding nebula's glow. Surprisingly complex details [ http://cdsads.u-strasbg.fr/cgi-bin/ nph-bib_query?1997ApJ...487..304H&db_key=AST&nosetcookie=1 ] and structures of NGC 6369 are revealed in this delightful color image [ http://heritage.stsci.edu/2002/25/index.html ] composed from Hubble Space Telescope data [ http://heritage.stsci.edu/2002/25/original.html ]. The nebula's main ring structure is about a light-year across and the glow from ionized oxygen, hydrogen, and nitrogen atoms are colored [ http://opostaff.stsci.edu/%7Elevay/process/ ] blue, green, and red respectively. Over 2,000 light-years away, the Little Ghost [ http://antwrp.gsfc.nasa.gov/apod/ap970331.html ] Nebula offers a glimpse of the fate of our Sun, which should produce its own pretty planetary nebula only about 5 billion years from now. |
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The Dumbbell Nebula in Hydro
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| Title |
The Dumbbell Nebula in Hydrogen and Oxygen |
| Explanation |
The first hint of what will become of our Sun [ http://www.nineplanets.org/sol.html ] was discovered inadvertently in 1764. At that time, Charles Messier [ http://www.seds.org/messier/xtra/history/biograph.html ] was compiling a list of "annoying" diffuse objects not to be confused with "interesting" comets. The 27th object on Messier's list [ http://antwrp.gsfc.nasa.gov/apod/ap960626.html ], now known as M27 [ http://www.seds.org/messier/m/m027.html ] or the Dumbbell Nebula, is a planetary nebula [ http://antwrp.gsfc.nasa.gov/apod/planetary_nebulae.html ], the type of nebula our Sun [ http://antwrp.gsfc.nasa.gov/apod/sun.html ] will produce when nuclear fusion [ http://fusedweb.pppl.gov/ ] stops in its core. M27 [ http://antwrp.gsfc.nasa.gov/apod/ap020302.html ] is one of the brightest planetary nebulae [ http://www.seds.org/messier/planetar.html ] on the sky, and can be seen in the constellation [ http://www.att.virtualclassroom.org/vc99/vc_04/cons_stars/cons/hist_cons.html ] Vulpecula [ http://www.astronomical.org/constellations/vul.html ] with binoculars. It takes light about 1000 years to reach us from M27, shown above [ http://www.noao.edu/image_gallery/html/im0780.html ], digitally sharpened, in three isolated colors emitted by hydrogen [ http://pearl1.lanl.gov/periodic/elements/1.html ] and oxygen [ http://pearl1.lanl.gov/periodic/elements/8.html ]. Understanding the physics and significance of M27 [ http://www.seds.org/messier/twn/n6853x.html ] was well beyond 18th century science. Even today, many things remain mysterious about bipolar planetary nebula [ http://antwrp.gsfc.nasa.gov/apod/ap020106.html ] like M27, including the physical mechanism that expels a low-mass star's gaseous outer-envelope, leaving an X-ray [ http://www.treasure-troves.com/physics/X-Ray.html ] hot white dwarf [ http://www.sciencenet.org.uk/database/Physics/Stars/p01158c.html ]. |
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NGC 6369: The Little Ghost N
…
| Title |
NGC 6369: The Little Ghost Nebula |
| Explanation |
This pretty planetary nebula, cataloged as NGC 6369 [ http://rao.150m.com/NGC6369.html ], was discovered by 18th century astronomer William Herschel [ http://www.bath-preservation-trust.org.uk/museums/ herschel/ ] as he used a telescope to explore the medicinal constellation Ophiucus [ http://www.hawastsoc.org/deepsky/oph/index.html ]. Round and planet-shaped, the nebula is also relatively faint [ http://astro.isi.edu/reference/herschel.html ] and has acquired the popular moniker of Little Ghost Nebula. Planetary nebulae [ http://www.seds.org/messier/planetar.html ] in general are not [ http://antwrp.gsfc.nasa.gov/apod/ap020302.html ] at all related to planets, but instead are created at the end of a sun-like star's life as its outer layers expand [ http://antwrp.gsfc.nasa.gov/apod/ap010805.html ] into space while the star's core shrinks to become a white dwarf. The transformed white dwarf star [ http://antwrp.gsfc.nasa.gov/apod/ap000910.html ], seen near the center, radiates strongly at ultraviolet wavelengths and powers the expanding nebula's glow. Surprisingly complex details [ http://cdsads.u-strasbg.fr/cgi-bin/ nph-bib_query?1997ApJ...487..304H&db_key=AST&nosetcookie=1 ] and structures of NGC 6369 are revealed in this delightful color image [ http://heritage.stsci.edu/2002/25/index.html ] composed from Hubble Space Telescope data [ http://heritage.stsci.edu/2002/25/original.html ]. The nebula's main ring structure is about a light-year across and the glow from ionized oxygen, hydrogen, and nitrogen atoms are colored [ http://opostaff.stsci.edu/%7Elevay/process/ ] blue, green, and red respectively. Over 2,000 light-years away, the Little Ghost [ http://antwrp.gsfc.nasa.gov/apod/ap970331.html ] Nebula offers a glimpse of the fate of our Sun, which should produce its own pretty planetary nebula only about 5 billion years from now. |
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M27: The Dumbbell Nebula
| Title |
M27: The Dumbbell Nebula |
| Explanation |
The first hint of what will become of our Sun [ http://www.seds.org/nineplanets/nineplanets/sol.html ] was discovered inadvertently in 1764. At that time, Charles Messier [ http://www.seds.org/messier/xtra/history/biograph.html ] was compiling a list of "annoying" diffuse objects not to be confused with "interesting" comets. The 27th object on Messier's list [ http://antwrp.gsfc.nasa.gov/apod/ap960626.html ], now known as M27 or the Dumbbell Nebula [ http://www.seds.org/messier/m/m027.html ], is a planetary nebula [ http://antwrp.gsfc.nasa.gov/apod/ap971223.html ], the type of nebula our Sun [ http://antwrp.gsfc.nasa.gov/apod/ap971120.html ] will produce when nuclear fusion stops in its core. M27 is one of the brightest planetary nebulae [ http://www.seds.org/messier/planetar.html ] on the sky, and can be seen [ http://antwrp.gsfc.nasa.gov/apod/ap970220.html ] in the constellation Vulpecula [ http://galileo.gmu.edu/constellation/VUL.html ] with binoculars. It takes light about 1000 years to reach us from M27. Understanding the physics and significance of M27 [ http://www.seds.org/messier/twn/n6853x.html ] was well beyond 18th century science. Even today, many things remain mysterious about bipolar planetary nebula [ http://antwrp.gsfc.nasa.gov/apod/ap980119.html ] like M27, including the physical mechanism that expels a low-mass star's gaseous outer-envelope, leaving an X-ray [ http://antwrp.gsfc.nasa.gov/apod/lib/glossary.html#X-ray ] hot white dwarf [ http://antwrp.gsfc.nasa.gov/apod/ap971102.html ]. |
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M27: The Dumbbell Nebula
| Title |
M27: The Dumbbell Nebula |
| Explanation |
The first hint of what will become of our Sun [ http://www.nineplanets.org/sol.html ] was discovered inadvertently in 1764 [ http://en.wikipedia.org/wiki/1764 ]. At that time, Charles Messier [ http://www.seds.org/messier/xtra/history/biograph.html ] was compiling a list of diffuse objects not to be confused with comets. The 27th object on Messier's list [ http://antwrp.gsfc.nasa.gov/apod/ap960626.html ], now known as M27 [ http://www.seds.org/messier/m/m027.html ] or the Dumbbell Nebula, is a planetary nebula [ http://antwrp.gsfc.nasa.gov/apod/planetary_nebulae.html ], the type of nebula our Sun [ http://antwrp.gsfc.nasa.gov/apod/sun.html ] will produce when nuclear fusion [ http://fusedweb.pppl.gov/ ] stops in its core. M27 [ http://antwrp.gsfc.nasa.gov/apod/ap020302.html ] is one of the brightest planetary nebulae [ http://www.seds.org/messier/planetar.html ] on the sky, and can be seen in the constellation [ http://www.astro.wisc.edu/~dolan/constellations/constellations.html ] Vulpecula [ http://www.astronomical.org/portal/modules/wfsection/article.php?articleid=88 ] with binoculars. It takes light about 1000 years to reach us from M27, shown above [ http://www.noao.edu/outreach/aop/observers/m27.html ], digitally sharpened, in three standard colors. Understanding the physics and significance of M27 [ http://astro.nineplanets.org/twn/n6853x.html ] was well beyond 18th century science. Even today, many things remain mysterious about bipolar planetary nebula [ http://antwrp.gsfc.nasa.gov/apod/ap040201.html ] like M27, including the physical mechanism that expels a low-mass star's gaseous outer-envelope, leaving an X-ray [ http://www.treasure-troves.com/physics/X-Ray.html ] hot white dwarf [ http://imagine.gsfc.nasa.gov/docs/science/know_l2/dwarfs.html ]. |
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