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A bright comet is moving into the evening skies. C/2023 A3 (Tsuchinshan–ATLAS) has brightened and even though it is now easily visible to the unaided eye, it is so near to the Sun that it is still difficult to see. Pictured, Comet Tsuchinshan–ATLAS was captured just before sunrise from an Andes Mountain in Peru. Braving cold weather, this unusually high perch gave the astrophotographer such a low eastern horizon that the comet was obvious in the pre-dawn sky. Visible in the featured image is not only an impressively long dust tail extending over many degrees, but an impressively long and blue ion tail, too. This month, as the comet moves out from the Sun and passes the Earth, evening observers should be able to see the huge dirty ice ball toward the west just after sunset. Growing Gallery: Comet Tsuchinsan-ATLAS in 2024
2024-10-07 Jose Santivañez Mueras
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The great variety of star colors in this open cluster underlie it's name: The Jewel Box. The bright central star Kappa Crucis is red, in contrast to the many blue stars that surround it. The cluster contains just over 100 stars, and might be no older than 10 million years. Open clusters are younger, contain few stars, and contain a much higher fraction of blue stars than do globular clusters. This Jewel Box lies about 7500 light-years away, so the light that we see today was emitted from the clusters before even the Great Pyramids in Egypt were built.
1996-11-11 Anglo-Australian Telescope Board
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Many spiral galaxies have bars across their centers. Even our own Milky Way Galaxy is thought to have a modest central bar. Prominently barred spiral galaxy NGC 6217, featured here, was captured in spectacular detail in this image taken by the Advanced Camera for Surveys on the orbiting Hubble Space Telescope in 2009. Visible are dark filamentary dust lanes, young clusters of bright blue stars, red emission nebulas of glowing hydrogen gas, a long bar of stars across the center, and a bright active nucleus that likely houses a supermassive black hole. Light takes about 60 million years to reach us from NGC 6217, which spans about 30,000 light years across and can be found toward the constellation of the Little Bear (Ursa Minor). APOD in world languages: Arabic, Bulgarian, Catalan, Chinese (Beijing), Chinese (Taiwan), Croatian, Czech, Dutch, French, French (Canada), German, Hebrew, Indonesian, Japanese, Korean, Montenegrin, Polish, Russian, Serbian, Slovenian, Spanish, Taiwanese, Turkish, Turkish, and Ukrainian
2022-02-21
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The Crab Nebula resulted from a star that exploded - a supernova. Although the stellar explosion that caused the Crab Nebula was seen over 900 years ago, the nebula itself still expands and shines. Much of the emitted light has been found to be polarized. Light waves with the same polarization vibrate in the same plane. Light waves can be polarized by reflection from a surface, an effect familiar to sunglass wearing fishermen and skiers. Polarized light can also be emitted by regions that contain strong magnetic fields. Areas of different polarization above are highlighted by different colors. Mapping the polarization helps astronomers decipher which physical processes create the observed light.
1995-11-23 AATB, Caltech, David Malin, Jay Pasachoff
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What's that red ring in the sky? Lightning. The most commonly seen type of lightning involves flashes of bright white light between clouds. Over the past 50 years, though, other types of upper-atmospheric lightning have been confirmed, including red sprites and blue jets. Less well known and harder to photograph is a different type of upper atmospheric lightning known as ELVES. ELVES are thought to be created when an electromagnetic pulse shoots upward from charged clouds and impacts the ionosphere, causing nitrogen molecules to glow. The red ELVES ring pictured had a radius of about 350 km and was captured in late March about 100 kilometers above Ancona, Italy. Years of experience and ultra-fast photography were used to capture this ELVES -- which lasted only about 0.001 second.
2023-04-17 Valter Binotto
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Carinae may be about to explode. But no one knows when - it may be next year, it may be one million years from now. Eta Carinae's mass - about 100 times greater than our Sun - make it an excellent candidate for a full blown supernova. Historical records do show that about 150 years ago Eta Carinae underwent an unusual outburst that made it one of the brightest stars in the southern sky. Eta Carinae, in the Keyhole Nebula, is the only star currently thought to emit natural LASER light. This just-released image taken last September resulted from sophisticated image-processing procedures designed to bring out new details in the unusual nebula that surrounds this rogue star. Now clearly visible are two distinct lobes, a hot central region, and strange radial streaks. The lobes are filled with lanes of gas and dust which absorb the blue and ultraviolet light emitted near the center. The streaks remain unexplained. Will these clues tell us how the nebula was formed? Will they better indicate when Eta Carinae will explode?
1996-06-11
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This gorgeous galaxy and comet portrait was recorded on April 5th in the skies over the Oriental Pyrenees near Figueres, Spain. From a site above 1,100 meters, astrophotographer Juan Carlos Casado used a guided time exposure, fast film, and a telephoto lens to capture the predicted conjunction of the bright Comet Ikeya-Zhang (right) and the Andromeda Galaxy (left). This stunning celestial scene would also have been a rewarding one for the influential 18th century comet hunter Charles Messier. While Messier scanned French skies for comets, he carefully cataloged positions of things which were fuzzy and comet-like in appearance but did not move against the background stars and so were definitely not comets. The Andromeda Galaxy, also known as M31, is the 31st object in his famous not-a-comet catalog. Not-a-comet object number 110, a late addition to Messier's catalog, is one of Andromeda's small satellite galaxies, and can be seen here just below M31. Our modern understanding holds that the Andromeda galaxy is a large spiral galaxy some 2 million light-years distant. The photogenic Comet Ikeya-Zhang, now a lovely sight in early morning skies, is about 80 million kilometers (4 light-minutes) from planet Earth.
2002-04-12 Juan Carlos Casado
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Tomorrow, December 10, the Full Moon will slide through planet Earth's shadow in a total lunar eclipse. The entire eclipse sequence, including 51 minutes of totality, will be visible from Asia and Australia, but moonwatchers in Europe and Africa will miss out on the beginning partial phases because for them, the eclipse will start before moonrise. In central and western North America the earlier phases of the eclipse will be in progress as the Moon sets. In fact, while those in the east will miss out, North Americans far enough west could see a scene very much like this one, with a mostly eclipsed Moon low and near the western horizon during morning twilght. This morning twilight view of another lunar eclipse approaching its total phase at moonset was captured in 2008 on February 21, from the Zagros Mountains of Iran. Lunar eclipse times and visibility: chart (pdf) | calculator
2011-12-09 Babak Tafreshi
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Slung below its equally innovative mothership dubbed White Knight, SpaceShipOne rides above planet Earth, photographed during a recent flight test. SpaceShipOne was designed and built by cutting-edge aeronautical engineer Burt Rutan and his company Scaled Composites to compete for the X Prize. The 10 million dollar X prize is open to private companies and requires the successful launch of a spaceship which carries three people on short sub-orbital flights to an altitude of 100 kilometers -- a scenario similar to the early manned spaceflights of NASA's Mercury Program. Unlike more conventional rocket flights to space, SpaceShipOne will first be carried to an altitude of 50,000 feet by the twin turbojet White Knight and then released before igniting its own hybrid solid fuel rocket engine. After the climb to space, the craft will convert to a stable high drag configuration for re-entry, ultimately landing like a conventional glider at light plane speeds.
2003-06-27
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It's no wonder Jupiter is a favorite target for even modest earthbound telescopes. The most massive planet in the solar system with four of the largest moons also boasts the famous Great Red Spot, a giant hurricane-like storm system over three hundred years old. Recorded on December 15, 2002 between 7:19 and 8:40 UT, over a thousand digital images were processed and stacked to create this spectacular 21 frame animation of the Jovian system. South is up and as the Great Red Spot tracks across the face of Jupiter, innermost Galilean moon Io enters the scene at the far right. Io occults (passes in front of) the edge of the more sedately orbiting Ganymede with Io's shadow moving quickly across the gas giant's cloud tops, just below the Red Spot. While the moon Callisto is outside the field of view, its large, dark shadow is also visible crossing the Jovian disk at the upper left. Viewed from Earth, the orbits of the Galilean moons presently lie nearly edge-on, offering many chances to observe similar dances of Jupiter's moons.
2003-02-27 Wes Higgins