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| Risultati della ricerca nelle immagini - "Telescope" |
006-Ceres.jpg1-Ceres (natural colors, from HST - credits: NASA/ESA et al.)54 visiteThe Hubble image of Ceres on the reveals bright and dark regions on the asteroid's surface that could be topographic features, such as craters, and/or areas containing different surface material. Large impacts may have caused some of these features and potentially added new material to the landscape. The Texas-sized asteroid holds about 30 to 40% of the mass in the Asteroid Belt.
Ceres' round shape suggests that its interior is layered like those of terrestrial planets such as Earth. The asteroid may have a rocky inner core, an icy mantle, and a thin, dusty outer crust. The asteroid may even have water locked beneath its surface. It is approx. 590 miles (950 Km) across and was the first asteroid discovered in 1801.
The observation was made in visible and ultraviolet light between December 2003 and January 2004 with the HST Advanced Camera for Surveys. The color variations in the image show either a difference in texture or composition on Ceres' surface.
Astronomers need the close-up views of the Dawn spacecraft to determine the characteristics of these regional differences.
MareKromium
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015-Ceres_and_Vesta.jpg4-Vesta and 1-Ceres from HST (natural colors)54 visiteThese Hubble Space Telescope images of Vesta and 1-Ceres show two of the most massive asteroids in the Asteroid Belt, a Region between Mars and Jupiter.
The images are helping astronomers plan for the Dawn spacecraft’s tour of these hefty asteroids. On July 7, 2007, NASA is scheduled to launch the spacecraft on a 4-year journey to the Asteroid Belt. Once there, Dawn will do some asteroid-hopping, going into orbit around Vesta in 2011 and Ceres in 2015. Dawn will be the first spacecraft to orbit two targets. At least 100.000 asteroids inhabit the Asteroid Belt, a reservoir of leftover material from the formation of our Solar-System planets some 4,6 Billion Years (BY) ago.MareKromium
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021-Vesta-3.jpgMoments of 4-Vesta54 visiteTo prepare for the Dawn spacecraft's visit to Vesta, astronomers used Hubble's Wide Field Planetary Camera 2 to snap new images of the asteroid. These images were taken on May 14 and 16, 2007. Each frame shows time in hours and minutes based on Vesta's 5,34-hour rotation period. Using Hubble, astronomers mapped Vesta's Southern Hemisphere, a Region dominated by a giant impact crater formed by a collision billions of years ago. The crater is 285 miles (456 Km) across, which is nearly equal to Vesta's 330-mile (530-Km) diameter.
Hubble's sharp "eye" can see features as small as about 37 miles (60 Km) across. The images show the difference in brightness and color on the asteroid's surface. These characteristics hint at the large-scale features that the Dawn spacecraft will see when it arrives at Vesta in 2011.
Hubble's view reveals extensive global features stretching longitudinally from the Northern Hemisphere to the Southern Hemisphere.
The images also show widespread differences in brightness in the east and west, which probably reflects compositional changes. Both of these characteristics could reveal volcanic activity throughout Vesta. The size of these different regions varies. Some are hundreds of miles across.
The brightness differences could be similar to the effect seen on the Moon, where smooth, dark regions are more iron-rich than the brighter highlands that contain minerals richer in calcium and aluminum. When Vesta was forming 4.5 billion years ago, it was heated to the melting temperatures of rock. This heating allowed heavier material to sink to Vesta's center and lighter minerals to rise to the surface.
Astronomers combined images of Vesta in two colors to study the variations in iron-bearing minerals. From these minerals, they hope to learn more about Vesta's surface structure and composition. Astronomers expect that Dawn will provide rich details about the asteroid's surface and interior structure.
MareKromium
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30-Doradus.jpg30 Doradus and R-13654 visiteThe massive, young stellar grouping, called R136, is only a few million years old and resides in the 30 Doradus Nebula, a turbulent star-birth region in the Large Magellanic Cloud (LMC), a satellite galaxy of our Milky Way. Many of the stars are among the most massive known. Several of them are over 100 times more massive than our Sun. These hefty stars are destined to become supernovae in a few million years.
The image, taken by Hubble's Wide Field Camera 3, spans about 100 light-years. The nebula is close enough to Earth that Hubble can resolve individual stars, giving astronomers important information about the stars' birth and evolution.
The brilliant stars are carving deep cavities in the surrounding material by unleashing a torrent of ultraviolet light, and hurricane-force stellar winds (streams of charged particles), which are etching away the enveloping hydrogen gas cloud in which the stars were born. The image reveals a fantasy landscape of pillars, ridges, and valleys, as well as a dark region in the center that roughly looks like the outline of a holiday tree. Besides sculpting the gaseous terrain, the brilliant stars can also help create a successive generation of offspring. When the winds hit dense walls of gas, they create shocks, which may be generating a new wave of star birth.
The movement of the LMC around the Milky Way may have triggered the massive cluster's formation in several ways. The gravitational tug of the Milky Way and the companion Small Magellanic Cloud may have compressed gas in the LMC. Also, the pressure resulting from the LMC plowing through the Milky Way's halo may have compressed gas in the satellite. The cluster is a rare, nearby example of the many super star clusters that formed in the distant, early universe, when star birth and galaxy interactions were more frequent. Previous Hubble observations have shown astronomers that super star clusters in faraway galaxies are ubiquitous. The LMC is located 170,000 light-years away and is a member of the Local Group of Galaxies, which also includes the Milky Way.
The Hubble image was taken at infrared wavelengths (1.1 microns and 1.6 microns). Hubble sees through the dusty nebula, revealing many stars that cannot be seen in visible light. The large bright star just above the center of the image is in the 30 Doradus nebula. The Hubble observations of 30 Doradus were made October 20-27, 2009.MareKromium
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30-Doradus_and_R-136.jpg30 Doradus and R-13657 visiteJust in time for the holidays: a Hubble Space Telescope picture postcard of hundreds of brilliant blue stars wreathed by warm, glowing clouds. The festive portrait is the most detailed view of the largest stellar nursery in our local galactic neighborhood. The massive, young stellar grouping, called R136, is only a few million years old and resides in the 30 Doradus Nebula, a turbulent star-birth region in the Large Magellanic Cloud (LMC), a satellite galaxy of our Milky Way. There is no known star-forming region in our galaxy as large or as prolific as 30 Doradus. Many of the diamond-like icy blue stars are among the most massive stars known. Several of them are over 100 times more massive than our Sun. These hefty stars are destined to pop off, like a string of firecrackers, as supernovas in a few million years.
The image, taken in ultraviolet, visible, and red light by Hubble's Wide Field Camera 3, spans about 100 light-years. The nebula is close enough to Earth that Hubble can resolve individual stars, giving astronomers important information about the birth and evolution of stars in the universe. The Hubble observations were taken Oct. 20-27, 2009. The blue color is light from the hottest, most massive stars; the green from the glow of oxygen; and the red from fluorescing hydrogen.MareKromium
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47 Tucanae-00.jpg47 Tucanae53 visite"...Crescit amor numni quantum ipsa pecunia crescit..."
(Giovenale)
"...L'amore per il denaro (che non si ha) cresce al crescere del denaro che (già) si possiede..."
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ARP-147.jpgARP 14753 visiteJust a couple of days after the orbiting observatory was brought back online, Hubble aimed its prime working camera, the Wide Field Planetary Camera 2 (WFPC2), at a particularly intriguing target, a pair of Gravitationally Interacting Galaxies called Arp 147.
The image demonstrated that the camera is working exactly as it was before going offline, thereby scoring a "perfect 10" both for performance and beauty.
The two galaxies happen to be oriented so that they appear to mark the number 10. The left-most galaxy, or the "one" in this image, is relatively undisturbed apart from a smooth ring of starlight. It appears nearly on edge to our line of sight. The right-most galaxy, resembling a zero, exhibits a clumpy, blue ring of intense star formation.
The blue ring was most probably formed after the galaxy on the left passed through the galaxy on the right. Just as a pebble thrown into a pond creates an outwardly moving circular wave, a propagating density wave was generated at the point of impact and spread outward. As this density wave collided with material in the target galaxy that was moving inward due to the gravitational pull of the two galaxies, shocks and dense gas were produced, stimulating star formation.
The dusty reddish knot at the lower left of the blue ring probably marks the location of the original nucleus of the galaxy that was hit.
Arp 147 appears in the Arp Atlas of Peculiar Galaxies, compiled by Halton Arp in the 1960s and published in 1966.
This picture was assembled from WFPC2 images taken with three separate filters. The blue, visible-light, and infrared filters are represented by the colors blue, green, and red, respectively.
The galaxy pair was photographed on October 27-28, 2008. Arp 147 lies in the constellation Cetus, and it is more than 400 MLY away from Earth.MareKromium
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ARP194-HST-2009-18-a-full_jpg.jpgArp 194 (Galaxy Cluster)53 visiteTo commemorate the Hubble Space Telescope's 19 years of historic, trailblazing science, the orbiting telescope has photographed a peculiar system of galaxies known as Arp 194. This interacting group contains several galaxies, along with a "cosmic fountain" of stars, gas, and dust that stretches over 100.000 LY.
The Northern (upper) component of Arp 194 appears as a haphazard collection of dusty spiral arms, bright blue star-forming regions, and at least two Galaxy Nuclei that appear to be connected and in the early stages of merging. A third, relatively normal, spiral galaxy appears off to the right.
The Southern (lower) component of the galaxy group contains a single large spiral galaxy with its own blue star-forming regions.
However, the most striking feature of this galaxy troupe is the impressive blue stream of material extending from the Northern Component. This "fountain" contains complexes of "Super Star Clusters", each one of which may contain dozens of individual young Star Clusters. The blue color is produced by the hot, massive stars which dominate the light in each cluster. Overall, the "fountain" contains many millions of stars.
These young star clusters probably formed as a result of the interactions between the galaxies in the Northern Component of Arp 194. The compression of gas involved in galaxy interactions can enhance the star-formation rate and give rise to brilliant bursts of star formation in merging systems.
Hubble's resolution shows clearly that the stream of material lies in front of the southern component of Arp 194, as evidenced by the dust that is silhouetted around the star-cluster complexes. It is therefore not entirely clear whether the southern component actually interacts with the northern pair.
The details of the interactions among the multiple galaxies that make up Arp 194 are complex. The shapes of all the galaxies involved appear to have been distorted, possibly by their gravitational interactions with one another.
Arp 194, located in the constellation Cepheus, resides approximately 600 MLY away from Earth. It contains some of the many interacting and merging galaxies known in our relatively nearby universe. These observations were taken in January of 2009 with the Wide Field Planetary Camera 2. Images taken through blue, green, and red filters were combined to form this picturesque image of galaxy interaction.MareKromium
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ARP_274-HST-2009-14-a-print.jpgGalaxy Triplet Arp 27453 visiteArp 274, also known as NGC 5679, is a system of 3 galaxies that appear to be partially overlapping in the image, although they may be at somewhat different distances. The spiral shapes of 2 of these galaxies appear mostly intact. The third galaxy (to the far left) is more compact, but shows evidence of star formation.
Two of the three galaxies are forming new stars at a high rate. This is evident in the bright blue knots of star formation that are strung along the arms of the galaxy on the right and along the small galaxy on the left.
The largest component is located in the middle of the triplet. It appears as a Spiral Galaxy, which may be barred. The entire system resides at about 400 Million Light-Years away from Earth in the Virgo constellation.
Hubble's Wide Field Planetary Camera 2 was used to image Arp 274. Blue, visible, and infrared filters were combined with a filter that isolates hydrogen emission. The colors in this image reflect the intrinsic color of the different stellar populations that make up the galaxies. Yellowish older stars can be seen in the central bulge of each galaxy.
A bright central cluster of stars pinpoint each nucleus. Younger blue stars trace the spiral arms, along with pinkish nebulae that are illuminated by new star formation. Interstellar dust is silhouetted against the starry population. A pair of foreground stars inside our own Milky Way are at far right.MareKromium
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Abell-520.jpgAbell 520: Cluster Crash Illuminates Dark Matter Conundrum99 visite"...Risponderò come da me si suole
Liberi sensi, in libere parole..."
T. Tasso, "Gerusalemme Liberata", 2, 81MareKromium
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BHR71-PIA09338.jpgProtostellar Jet in BHR 71 Dark Cloud53 visiteTwo rambunctious young stars are destroying their natal dust cloud with powerful jets of radiation, in an infrared image from NASA's Spitzer Space Telescope.
The stars are located approximately 600 light-years away in a cosmic cloud called BHR 71. In visible light (left panel), BHR 71 is just a large black structure. The burst of yellow light toward the bottom of the cloud is the only indication that stars might be forming inside. In infrared light (center panel), the baby stars are shown as the bright yellow smudges toward the center. Both of these yellow spots have wisps of green shooting out of them. The green wisps reveal the beginning of a jet. Like a rainbow, the jet begins as green, then transitions to orange, and red toward the end. The combined visible-light and infrared composite (right panel) shows that a young star's powerful jet is responsible for the rupture at the bottom of the dense cloud in the visible-light image. Astronomers know this because burst of light in the visible-light image overlaps exactly with a jet spouting-out of the left star, in the infrared image.
The jets' changing colors reveal a cooling effect, and may suggest that the young stars are spouting out radiation in regular bursts. The green tints at the beginning of the jet reveal really hot hydrogen gas, the orange shows warm gas, and the reddish wisps at the end represent the coolest gas. The fact that gas toward the beginning of the jet is hotter than gas near the middle suggests that the stars must give off regular bursts of energy -- and the material closest to the star is being heated by shockwaves from a recent stellar outburst. Meanwhile, the tints of orange reveal gas that is currently being heated by shockwaves from a previous stellar outburst. By the time these shockwaves reach the end of the jet, they have slowed down so significantly that the gas is only heated a little, and looks red. The combination of views also brings out some striking details that evaded visible-light detection. For example, the yellow dots scattered throughout the image are actually young stars forming inside BHR 71. Spitzer also uncovered another young star with jets, located to the right of the powerful jet seen in the visible-light image. Spitzer can see details that visible-light telescopes don't, because its infrared instruments are sensitive to "heat."
The infrared image is made up of data from Spitzer's infrared array camera. Blue shows infrared light at 3.6 microns, green is light at 4.5 microns, and red is light at 8.0 microns.
MareKromium
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Binary Black Hole.jpgBinary Black Hole in 3C 7585 visite"...Docti non solum vivi atque presentes studiosos discendi erudiunt atque docent, sed hoc idem etiam post mortem monumentis litterarum assequuntur..."
(Cicerone)
"...I veri sapienti insegnano non solo durante la loro vita, ma anche una volta defunti, grazie alle Opere che ci lasciano..."
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