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Sharper Vision
| title |
Sharper Vision |
| date |
07.09.2004 |
| description |
The power of the Keck telescope's adaptive optics system is clear in this image of Uranus, its rings and the moon Miranda. The two sets of exposures compare Keck AO system off (left) to Keck AO system on (right). Upper: Uranus, its rings and moon Miranda at near infrared wavelengths of 2.2 microns. Lower: Uranus and its atmospheric details as seen in near infrared wavelengths of 1.6 microns. The image has been doubled in size. Date is Universal Time. *Image Credit*:Heidi Hammel, Space Science Institute, Boulder, CO/Imke de Pater, University of California, Berkeley/ W. M. Keck Observatory |
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Eris: The Largest Known Dwar
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| Title |
Eris: The Largest Known Dwarf Planet |
| Explanation |
Is Pluto the largest dwarf planet? No! Currently, the largest known dwarf planet is (136199) Eris [ http://en.wikipedia.org/wiki/136199_Eris ], renamed last week from 2003 UB313 [ http://antwrp.gsfc.nasa.gov/apod/ap060207.html ]. Eris is just slightly larger than Pluto, but orbits as far as twice Pluto [ http://antwrp.gsfc.nasa.gov/apod/ap060903.html ]'s distance from the Sun. Eris is shown above [ http://www.keckobservatory.org/view_album.php?album_id=4 ] in an image taken by a 10-meter Keck Telescope [ http://antwrp.gsfc.nasa.gov/apod/ap971227.html ] from Hawaii [ http://antwrp.gsfc.nasa.gov/apod/ap951216.html ], USA [ https://www.cia.gov/cia/publications/factbook/geos/us.html ]. Like Pluto, Eris has a moon, which has been officially named [ http://cfa-www.harvard.edu/iau/special/08747.pdf ] by the International Astronomical Union [ http://www.iau.org/ ] as (136199) Eris I (Dysnomia). Dysnomia [ http://en.wikipedia.org/wiki/Dysnomia_%28moon%29 ] is visible above just to the right of Eris. Dwarf planets [ http://en.wikipedia.org/wiki/Dwarf_planet ] Pluto and Eris are trans-Neptunian objects [ http://www.planetary.org/explore/topics/trans_neptunian_objects/ ] that orbit in the Kuiper belt [ http://www.ifa.hawaii.edu/~jewitt/kb.html ] of objects past Neptune. Eris [ http://antwrp.gsfc.nasa.gov/apod/ap050801.html ] was discovered in 2003, and is likely composed of frozen water-ice and methane [ http://en.wikipedia.org/wiki/Methane ]. Since Pluto's recent demotion by the IAU [ http://en.wikipedia.org/wiki/International_Astronomical_Union ] from planet to dwarf planet status, Pluto [ http://voyagesolarsystem.org/gallery/gallery_10.html ] has recently also been given a new numeric designation: (134340) Pluto. Currently, the only other officially designated "dwarf planet" is (1) Ceres [ http://antwrp.gsfc.nasa.gov/apod/ap060821.html ]. |
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Double Asteroid 90 Antiope
| Title |
Double Asteroid 90 Antiope |
| Explanation |
This eight-frame animation is based on the first ever images [ http://www.boulder.swri.edu/~merline/press/ ] of a double asteroid [ http://www.boulder.swri.edu/~merline/press/release.txt ]! Formerly thought to be a single enormous chunk of rock, asteroid 90 Antiope [ http://cfa-www.harvard.edu/iau/lists/ NumberedMPs00001.html ] resides in the solar system's [ http://space.jpl.nasa.gov/ ] main asteroid belt [ http://seds.lpl.arizona.edu/nineplanets/nineplanets/ asteroids.html ] between Mars and Jupiter. Now, these premier images reveal Antiope to actually consist of two 50 mile wide asteroids separated by about 100 miles. Like weights on each end of an elastic string, the pair mutually orbit [ http://hyperphysics.phy-astr.gsu.edu/hbase/ orbv.html#bo ] their center of mass, or balance point in the space between them, once every 16.5 hours. Binary asteroids and asteroids with moons [ http://antwrp.gsfc.nasa.gov/apod/ap991014.html ] are believed to be rare, but observations of their orbits allow a direct determination of asteroid masses and densities. Surprisingly, Antiope and known [ http://www.cfht.hawaii.edu/News/PR_001026/ ] asteroid-moon [ http://antwrp.gsfc.nasa.gov/apod/ap990807.html ] systems are found to have densities closer to ice than rock, despite their relatively dark and unreflective surfaces. These sharp images were made at the Keck Observatory atop the Hawaiian volcano Mauna Kea using newly developed adaptive optics [ http://www.mtwilson.edu/Science/ AdapOpt/Overview/ ] technology to overcome the blurring effect [ http://antwrp.gsfc.nasa.gov/apod/ap000725.html ] of Earth's atmosphere. |
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Land of Three Suns (Artist's
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PIA03520
Keck I Telescope
| Title |
Land of Three Suns (Artist's Concept Animation) |
| Original Caption Released with Image |
Figure 1: Sifting the Light of Three Suns This artist's animation shows the view from a hypothetical moon in orbit around the first known planet to reside in a tight-knit triple-star system. HD 188553 Ab is a gas giant planet, about 1.14 times the mass of Jupiter, with an orbital period of 3.3 days discovered using the Keck I telescope atop Mauna Kea in Hawaii, and zips around a single star that is orbited by a nearby pair of pirouetting stars. Because the stars in this triple system are bunched together, sunsets on the planet -- or on any moons that might exist around the planet -- would be spectacular. This rambunctious stellar family is called HD188753 and is located 149 light-years away in the constellation Cygnus. In this movie, sunset is seen through the tenuous atmosphere of a hot, baked hypothetical moon. As the suns dip below the horizon, the gas giant comes into view. The moon's landscape remains illuminated by sunlight reflected off the planet. Both the planet and moon would be so hot that even in shadow their surfaces would glow. The suns' colors and sizes reflect their masses, temperatures and distances to the planet. For example, the first star shown setting over the horizon is the closest, most massive and hottest of the trio, so it is depicted as large and white. The second star is farther away, less massive and cooler than the first, appearing smaller and yellow. The final star is at the same distance as the second, but it is still less massive and cooler, appearing even smaller and orange-red in color. Our Sun is a bit cooler than the hottest star of the system. The graph in figure 1 shows the "wobble" of a star being tugged on by the planet called HD 188753 Ab. The planet was discovered via the radial velocity technique, in which a planet's presence is inferred by the motion, or wobble, it causes in its parent star. Stellar motion is plotted here as changes in velocity (y-axis) versus time (x-axis). Unlike most planetary wobbles, this one comes from a star that is circled by a nearby pair of stars. In other words, the planet orbits a single star that is part of a close-knit triple-star system. Because the starlight from this cramped bunch blends together, the task of sifting through the light to find the planet's signature was more difficult. This challenge was overcome with the help of detailed models of the triple-star system's light. Data from those models resulted in precise velocity measurements of the star circled by HD 188753 Ab. Note: The size of the Full-Res TIFF for the still image is 3200 samples x 2400 lines. |
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Land of Three Suns (Artist's
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PIA03520
Keck I Telescope
| Title |
Land of Three Suns (Artist's Concept Animation) |
| Original Caption Released with Image |
Figure 1: Sifting the Light of Three Suns This artist's animation shows the view from a hypothetical moon in orbit around the first known planet to reside in a tight-knit triple-star system. HD 188553 Ab is a gas giant planet, about 1.14 times the mass of Jupiter, with an orbital period of 3.3 days discovered using the Keck I telescope atop Mauna Kea in Hawaii, and zips around a single star that is orbited by a nearby pair of pirouetting stars. Because the stars in this triple system are bunched together, sunsets on the planet -- or on any moons that might exist around the planet -- would be spectacular. This rambunctious stellar family is called HD188753 and is located 149 light-years away in the constellation Cygnus. In this movie, sunset is seen through the tenuous atmosphere of a hot, baked hypothetical moon. As the suns dip below the horizon, the gas giant comes into view. The moon's landscape remains illuminated by sunlight reflected off the planet. Both the planet and moon would be so hot that even in shadow their surfaces would glow. The suns' colors and sizes reflect their masses, temperatures and distances to the planet. For example, the first star shown setting over the horizon is the closest, most massive and hottest of the trio, so it is depicted as large and white. The second star is farther away, less massive and cooler than the first, appearing smaller and yellow. The final star is at the same distance as the second, but it is still less massive and cooler, appearing even smaller and orange-red in color. Our Sun is a bit cooler than the hottest star of the system. The graph in figure 1 shows the "wobble" of a star being tugged on by the planet called HD 188753 Ab. The planet was discovered via the radial velocity technique, in which a planet's presence is inferred by the motion, or wobble, it causes in its parent star. Stellar motion is plotted here as changes in velocity (y-axis) versus time (x-axis). Unlike most planetary wobbles, this one comes from a star that is circled by a nearby pair of stars. In other words, the planet orbits a single star that is part of a close-knit triple-star system. Because the starlight from this cramped bunch blends together, the task of sifting through the light to find the planet's signature was more difficult. This challenge was overcome with the help of detailed models of the triple-star system's light. Data from those models resulted in precise velocity measurements of the star circled by HD 188753 Ab. Note: The size of the Full-Res TIFF for the still image is 3200 samples x 2400 lines. |
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