wez Posted May 7, 2009 Author Posted May 7, 2009 A Halo for NGC 6164 Credit & Copyright: Don Goldman [attach=full]1880[/attach] Explanation: Beautiful emission nebula NGC 6164 was created by a rare, hot, luminous O-type star, some 40 times as massive as the Sun. Seen at the center of the cosmic cloud, the star is a mere 3 to 4 million years old. In another three to four million years the massive star will end its life in a supernova explosion. Spanning around 4 light-years, the nebula itself has a bipolar symmetry. That makes it similar in appearance to more familiar planetary nebulae - the gaseous shrouds surrounding dying sun-like stars. Also like many planetary nebulae, NGC 6164 has been found to have an extensive, faint halo, revealed in this deep telescopic image of the region. Expanding into the surrounding interstellar medium, the material in the halo is likely from an earlier active phase of the O star. The gorgeous skyscape is a composite of narrow-band image data highlighting the glowing gas, and broad-band data of the surrounding starfield. NGC 6164 is 4,200 light-years away in the southern constellation of Norma. Quote
wez Posted May 9, 2009 Author Posted May 9, 2009 Galaxies of the Perseus Cluster Credit & Copyright: R. Jay Gabany [attach=full]1881[/attach] Explanation: This colorful telescopic skyscape is filled with galaxies that lie nearly 250 million light-years away, the galaxies of the Perseus cluster. Their extended and sometimes surprising shapes are seen beyond a veil of foreground stars in our own Milky Way. Ultimately consisting of over a thousand galaxies, the cluster is filled with yellowish elliptical and lenticular galaxies, like those scattered throughout this view of the cluster's central region. Notably, the large galaxy at the left is the massive and bizarre-looking NGC 1275. A prodigious source of high-energy emission, active galaxy NGC 1275 dominates the Perseus cluster, accreting matter as entire galaxies fall into it and feed the supermassive black hole at the galaxy's core. Of course, spiral galaxies also inhabit the Perseus cluster, including the small, face-on spiral NGC 1268, right of picture center. The bluish spot on the outskirts of NGC 1268 is supernova SN 2008fg. At the estimated distance of the Perseus galaxy cluster, this field spans about 1.5 million light-years. Quote
wez Posted May 26, 2009 Author Posted May 26, 2009 Whirlpool Galaxy Deep Field Credit & Copyright: Jon Christensen [attach=full]1882[/attach] Explanation: Follow the handle of the Big Dipper away from the dipper's bowl, until you get to the handle's last bright star. Then, just slide your telescope a little south and west and you might find this stunning pair of interacting galaxies, the 51st entry in Charles Messier's famous catalog. Perhaps the original spiral nebula, the large galaxy with well defined spiral structure is also cataloged as NGC 5194. Its spiral arms and dust lanes clearly sweep in front of its companion galaxy (left), NGC 5195. The pair are about 31 million light-years distant and officially lie within the angular boundaries of the small constellation Canes Venatici. Though M51 looks faint and fuzzy to the human eye, the above long-exposure, deep-field image taken last month shows much of the faint complexity that actually surrounds the smaller galaxy. Quote
wez Posted June 30, 2009 Author Posted June 30, 2009 The North America and Pelican Nebulae Credit & Copyright: Danny Lee Russell [attach=full]1883[/attach] Explanation: Here are some familiar shapes in unfamiliar locations. This emission nebula on the left is famous partly because it resembles Earth's continent of North America. To the right of the North America Nebula, cataloged as NGC 7000, is a less luminous nebula that resembles a pelican dubbed the Pelican Nebula. The two emission nebula measure about 50 light-years across, are located about 1,500 light-years away, and are separated by a dark absorption cloud. This spectacular image captures the nebulas, bright ionization fronts, and fine details of the dark dust. The nebulae can be seen with binoculars from a dark location. Look for a small nebular patch north-east of bright star Deneb in the constellation of Cygnus. It is still unknown which star or stars ionize the red-glowing hydrogen gas. Quote
wez Posted July 8, 2009 Author Posted July 8, 2009 The Trifid Nebula in Stars and Dust Credit & Copyright: Adam Block, Mt. Lemmon SkyCenter, U. Arizona [attach=full]1884[/attach] Explanation: Unspeakable beauty and unimaginable bedlam can be found together in the Trifid Nebula. Also known as M20, this photogenic nebula is visible with good binoculars towards the constellation of Sagittarius. The energetic processes of star formation create not only the colors but the chaos. The red-glowing gas results from high-energy starlight striking interstellar hydrogen gas. The dark dust filaments that lace M20 were created in the atmospheres of cool giant stars and in the debris from supernovae explosions. Which bright young stars light up the blue reflection nebula is still being investigated. The light from M20 we see today left perhaps 3,000 years ago, although the exact distance remains unknown. Light takes about 50 years to cross M20. Quote
wez Posted July 28, 2009 Author Posted July 28, 2009 A Floral Aurora Corona Credit & Copyright: Zoltan Kenwell (Infocus Imagery) [attach=full]1885[/attach] Explanation: Few auroras show this level of detail. Above, a standard digital camera captured a particularly active and colorful auroral corona that occurred last week above Alberta, Canada. With a shape reminiscent of a flower, the spectacular aurora had an unusually high degree of detail. The vivid green and purple auroral colors are caused by high atmospheric oxygen and hydrogen reacting to a burst of incoming electrons. Many photogenic auroras have been triggered from a solar wind stream that recently passed the Earth. The auroras were unexpected because the initiating Sun has been unusually quiet of late. Quote
wez Posted August 2, 2009 Author Posted August 2, 2009 Stars, Dust and Nebula in NGC 6559 Credit & Copyright: Adam Block, Mt. Lemmon SkyCenter, U. Arizona [attach=full]1886[/attach] Explanation: When stars form, pandemonium reigns. A textbook case is the star forming region NGC 6559. Visible above are red glowing emission nebulas of hydrogen, blue reflection nebulas of dust, dark absorption nebulas of dust, and the stars that formed from them. The first massive stars formed from the dense gas will emit energetic light and winds that erode, fragment, and sculpt their birthplace. And then they explode. The resulting morass can be as beautiful as it is complex. After tens of millions of years, the dust boils away, the gas gets swept away, and all that is left is a naked open cluster of stars. Quote
wez Posted August 4, 2009 Author Posted August 4, 2009 T Tauri: A Star is Formed Credit & Copyright: T. Rector (U. Alaska Anchorage), H. Schweiker, WIYN, NOAO, AURA, NSF [attach=full]1887[/attach] Explanation: What does a star look like when it is forming? The prototypical example is the variable star T Tauri, visible as the bright orange star near the image center. The orange star centered in this remarkable telescopic skyview is T Tauri, prototype of the class of T Tauri variable stars. Surrounding T Tauri is a dusty yellow cosmic cloud named the Hind's Variable Nebula (NGC 1555/1554). Over 400 light-years away, at the edge of a molecular cloud, both star and nebula are seen to vary significantly in brightness but not necessarily at the same time, adding to the mystery of the intriguing region. T Tauri stars are now generally recognized as young -- less than a few million years old -- sun-like stars still in the early stages of formation. To further complicate the picture, infrared observations indicate that T Tauri itself is part of a multiple star system. Surprisingly, due to a close gravitational pass near one of these stars, T Tauri may now be headed out of the system. The dramatic color image above captures a region that spans about 4 light-years. Quote
wez Posted August 22, 2009 Author Posted August 22, 2009 The Gum Nebula Credit & Copyright: Axel Mellinger [attach=full]1888[/attach] Explanation: Named for Australian astronomer Colin Stanley Gum (1924-1960), The Gum Nebula is so large and close it is actually hard to see. In fact, we are only about 450 light-years from the front edge and 1,500 light-years from the back edge of this cosmic cloud of glowing hydrogen gas. Covered in this 41 degree-wide mosaic of H-alpha images, the faint emission region is otherwise easy to lose against the background of Milky Way stars. The complex nebula is thought to be a supernova remnant over a million years old, sprawling across the southern constellations Vela and Puppis. Sliding your cursor over this spectacular wide field view will reveal the location of objects embedded in The Gum Nebula, including the Vela supernova remnant. Quote
wez Posted August 26, 2009 Author Posted August 26, 2009 Classic Orion Nebulae Credit & Copyright: Kerry-Ann Lecky Hepburn (Weather and Sky Photography) [attach=full]1889[/attach] Explanation: The Great Nebula in Orion, also known as M42, is one of the most famous nebulae in the sky. The star forming region's glowing gas clouds and hot young stars are near the center of this colorful deep sky image that includes the smaller nebula M43 and dusty, bluish reflection nebulae NGC 1977 and friends on the left. Located at the edge of an otherwise invisible giant molecular cloud complex, these eye-catching nebulae represent only a small fraction of this galactic neighborhood's wealth of interstellar material. Captured with very modest equipment, the gorgeous skyscape was awarded Best in Show at the 2009 Starfest International Salon of Astrophotography. Judges commented that the detail and shading were exquisite in this version of a classic astronomical image. The field spans nearly 3 degrees or about 75 light-years at the Orion Nebula's estimated distance of 1,500 light-years. Quote
wez Posted September 2, 2009 Author Posted September 2, 2009 Open Cluster M25 Credit & Copyright: Jean-Charles Cuillandre (CFHT) & Giovanni Anselmi (Coelum Astronomia), Hawaiian Starlight [attach=full]1890[/attach] Explanation: Many stars like our Sun were formed in open clusters. The above pictured open cluster, M25, contains thousands of stars and is about two thousand light years distant. The stars in this cluster all formed together about 90 million years ago. The bright young stars in M25 appear blue. Open clusters, also called galactic clusters, contain fewer and younger stars than globular clusters. Also unlike globular clusters, open clusters are generally confined to the plane of our Galaxy. M25 is visible with binoculars towards the constellation of the Archer ( Sagittarius). Quote
wez Posted September 5, 2009 Author Posted September 5, 2009 Supernova Remnant E0102-72 Credit: X-ray - NASA / CXC / MIT / D.Dewey et al., NASA / CXC / SAO / J.DePasquale; Optical - NASA / STScI [attach=full]1891[/attach] Explanation: The expanding debris cloud from the explosion of a massive star is captured in this multiwavelength composite, combining x-ray and optical images from the Chandra and Hubble telescopes. Identified as E0102-72, the supernova remnant lies about 190,000 light-years away in our neighboring galaxy, the Small Magellanic Cloud. A strong cosmic source of x-rays, E0102 was imaged by the Chandra X-ray Observatory shortly after its launch in 1999. In celebration of Chandra's 10th anniversary, this colorful view of E0102 and its environs was created, including additional Chandra data. An analysis of all the data indicates that the overall shape of E0102 is most likely a cylinder that is viewed end-on rather than a spherical bubble. The intriguing result implies that the massive star's explosion has produced a shape similar to what is seen in some planetary nebulae associated with lower mass stars. At the distance of the Small Magellanic Cloud, this field of view spans about 150 light-years. Quote
wez Posted September 10, 2009 Author Posted September 10, 2009 The Butterfly Nebula Credit: NASA, ESA, and the Hubble SM4 ERO Team [attach=full]1892[/attach] Explanation: The bright clusters and nebulae of planet Earth's night sky are often named for flowers or insects, and NGC 6302 is no exception. With an estimated surface temperature of about 250,000 degrees C, the central star of this particular planetary nebula is exceptionally hot though -- shining brightly in ultraviolet light but hidden from direct view by a dense torus of dust. Above is a dramatically detailed close-up of the dying star's nebula recorded by the newly upgraded Hubble Space Telescope. Cutting across a bright cavity of ionized gas, the dust torus surrounding the central star is in the upper right corner of this view, nearly edge-on to the line-of-sight. Molecular hydrogen has recently been detected in this hot star's dusty cosmic shroud. NGC 6302 lies about 4,000 light-years away in the arachnologically correct constellation Scorpius. 1 Quote
wez Posted September 15, 2009 Author Posted September 15, 2009 NGC 6888: The Crescent Nebula Credit & Copyright: Daniel L?pez, IAC [attach=full]1893[/attach] Explanation: NGC 6888, also known as the Crescent Nebula, is a cosmic bubble about 25 light-years across, blown by winds from its central, bright, massive star. This beautiful portrait of the nebula is from the Isaac Newton Telescope at Roque de los Muchachos Observatory in the Canary Islands. It combines a composite color image with narrow band data that isolates light from hydrogen and oxygen atoms in the wind-blown nebula. The oxygen atoms produce the blue-green hue that seems to enshroud the detailed folds and filaments. NGC 6888's central star is classified as a Wolf-Rayet star (WR 136). The star is shedding its outer envelope in a strong stellar wind, ejecting the equivalent of the Sun's mass every 10,000 years. The nebula's complex structures are likely the result of this strong wind interacting with material ejected in an earlier phase. Burning fuel at a prodigious rate and near the end of its stellar life this star should ultimately go out with a bang in a spectacular supernova explosion. Found in the nebula rich constellation Cygnus, NGC 6888 is about 5,000 light-years away. Quote
wez Posted September 29, 2009 Author Posted September 29, 2009 Orion in Gas, Dust, and Stars Credit & Copyright: Rogelio Bernal Andreo (Deep Sky Colors) [attach=full]1894[/attach] Explanation: The constellation of Orion holds much more than three stars in a row. A deep exposure shows everything from dark nebula to star clusters, all imbedded in an extended patch of gaseous wisps in the greater Orion Molecular Cloud Complex. The brightest three stars on the far left are indeed the famous three stars that make up the belt of Orion. Just below Alnitak, the lowest of the three belt stars, is the Flame Nebula, glowing with excited hydrogen gas and immersed in filaments of dark brown dust. Below the frame center and just to the right of Alnitak lies the Horsehead Nebula, a dark indentation of dense dust that has perhaps the most recognized nebular shapes on the sky. On the upper right lies M42, the Orion Nebula, an energetic caldron of tumultuous gas, visible to the unaided eye, that is giving birth to a new open cluster of stars. Immediately to the left of M42 is a prominent bluish reflection nebula sometimes called the Running Man that houses many bright blue stars. The above image, a digitally stitched composite taken over several nights, covers an area with objects that are roughly 1,500 light years away and spans about 75 light years. Quote
wez Posted October 17, 2009 Author Posted October 17, 2009 Herschel Views the Milky Way Credit: ESA, SPIRE & PACS Consortia [attach=full]1895[/attach] Explanation: With a 3.5 meter diameter mirror, larger than the Hubble Space Telescope, Herschel is ESA's new infrared observatory. The space-based telescope is named for German-born British astronomer Frederick William Herschel who discovered infrared light over 200 years ago. In initial tests, Herschel's cameras have combined to deliver this spectacular view along the plane of the Milky Way in the constellation of the Southern Cross. Spanning some 2 degrees the premier, false-color, far-infrared view captures our galaxy's cold dust clouds in extreme detail, showing a remarkable, connected maze of filaments and star-forming regions. These and planned future Herschel observations are intended to unravel mysteries of star formation by surveying broad areas of the galactic plane. Quote
wez Posted October 25, 2009 Author Posted October 25, 2009 M1: The Crab Nebula from Hubble Credit: NASA, ESA, J. Hester, A. Loll (ASU); Acknowledgement: Davide De Martin (Skyfactory) [attach=full]1896[/attach] Explanation: This is the mess that is left when a star explodes. The Crab Nebula, the result of a supernova seen in 1054 AD, is filled with mysterious filaments. The filaments are not only tremendously complex, but appear to have less mass than expelled in the original supernova and a higher speed than expected from a free explosion. The above image, taken by the Hubble Space Telescope, is presented in three colors chosen for scientific interest. The Crab Nebula spans about 10 light-years. In the nebula's very center lies a pulsar: a neutron star as massive as the Sun but with only the size of a small town. The Crab Pulsar rotates about 30 times each second. Quote
wez Posted October 30, 2009 Author Posted October 30, 2009 The Bubble and M52 Credit & Copyright: Tony Hallas [attach=full]1897[/attach] Explanation: To the eye, this cosmic composition nicely balances the Bubble Nebula at the upper right with open star cluster M52. The pair would be lopsided on other scales, though. Embedded in a complex of interstellar dust and gas and blown by the winds from a single, massive O-type star, the Bubble Nebula (aka NGC 7635) is a mere 10 light-years wide. On the other hand, M52 is a rich open cluster of around a thousand stars. The cluster is about 25 light-years across. Seen toward the northern boundary of Cassiopeia, distance estimates for the Bubble Nebula and associated cloud complex are around 11,000 light-years, while star cluster M52 lies nearly 5,000 light-years away. Quote
wez Posted October 31, 2009 Author Posted October 31, 2009 VdB 152: Reflection Nebula in Cepheus Credit & Copyright: Stephen Leshin [attach=full]1898[/attach] Explanation: Described as a "dusty curtain" or "ghostly apparition", mysterious reflection nebula VdB 152 really is very faint. Far from your neighborhood on this Halloween Night, the cosmic phantom is nearly 1,400 light-years away. Also cataloged as Ced 201, it lies along the northern Milky Way in the royal constellation Cepheus. Near the edge of a large molecular cloud, pockets of interstellar dust in the region block light from background stars or scatter light from the embedded bright star giving parts of the nebula a characteristic blue color. Ultraviolet light from the star is also thought to cause a dim reddish luminescence in the nebular dust. Though stars do form in molecular clouds, this star seems to have only accidentally wandered into the area, as its measured velocity through space is very different from the cloud's velocity. This deep telescopic image of the region spans about 7 light-years. Astronomy Picture of the Day Quote
wez Posted November 4, 2009 Author Posted November 4, 2009 Seven Sisters Versus California Credit & Copyright: Rogelio Bernal Andreo (Deep Sky Colors) [attach=full]1899[/attach] Explanation: On the upper right, dressed in blue, is the Pleiades. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and most easily visible open clusters on the sky. The Pleiades contains over 3,000 stars, is about 400 light years away, and only 13 light years across. Surrounding the stars is a spectacular blue reflection nebula made of fine dust. A common legend is that one of the brighter stars faded since the cluster was named. On the lower left, shining in red, is the California Nebula. Named for its shape, the California Nebula is much dimmer and hence harder to see than the Pleiades. Also known as NGC 1499, this mass of red glowing hydrogen gas is about 1,500 light years away. Although about 25 full moons could fit between them, the above wide angle, deep field image composite has captured them both. Quote
wez Posted November 6, 2009 Author Posted November 6, 2009 Ring Nebula Deep Field Credit & Copyright: Vicent Peris (DSA / OAUV / PixInsight), Jack Harvey (DSA / SSRO), Steve Mazlin (DSA / SSRO), Jose Luis Lamadrid (DSA / ceFca), Ana Guijarro (CAHA), RECTA, DSA. [attach=full]1900[/attach] Explanation: A familiar sight to sky enthusiasts with even a small telescope, the Ring Nebula (M57) is some 2,000 light-years away in the musical constellation Lyra. The central ring is about one light-year across, but this remarkably deep exposure - a collaborative effort combining data from three different telescopes - explores the looping filaments of glowing gas extending much farther from the nebula's central star. Of course, in this well-studied example of a planetary nebula, the glowing material does not come from planets. Instead, the gaseous shroud represents outer layers expelled from a dying, sun-like star. This remarkable composite image includes narrowband image data recording the Ring's atomic hydrogen emission (shown as violet) in visible light and molecular hydrogen emission (shown as red) at near infrared wavelengths. The much more distant spiral galaxy IC 1296 is also visible at the upper right. Quote
wez Posted November 7, 2009 Author Posted November 7, 2009 Stickney Crater Credit: HiRISE, MRO, LPL (U. Arizona), NASA [attach=full]1901[/attach] Explanation: Stickney Crater, the largest crater on the martian moon Phobos, is named for Chloe Angeline Stickney Hall, mathematician and wife of astronomer Asaph Hall. Asaph Hall discovered both the Red Planet's moons in 1877. Over 9 kilometers across, Stickney is nearly half the diameter of Phobos itself, so large that the impact that blasted out the crater likely came close to shattering the tiny moon. This stunning, enhanced-color image of Stickney and surroundings was recorded by the HiRISE camera onboard the Mars Reconnaissance Orbiter as it passed within some six thousand kilometers of Phobos in March of 2008. Even though the surface gravity of asteroid-like Phobos is less than 1/1000th Earth's gravity, streaks suggest loose material has slid down inside the crater walls over time. Light bluish regions near the crater's rim could indicate a relatively freshly exposed surface. The origin of the curious grooves along the surface is mysterious but may be related to the crater-forming impact. Quote
wez Posted November 11, 2009 Author Posted November 11, 2009 Saturn After Equinox Credit: Cassini Imaging Team, ISS, JPL, ESA, NASA [attach=full]1902[/attach] Explanation: The other side of Saturn's ring plane is now directly illuminated by the Sun. For the previous 15 years, the southern side of Saturn and its rings were directly illuminated, but since Saturn's equinox in August, the orientation has reversed. Pictured above last month, the robotic Cassini spacecraft orbiting Saturn has captured the giant planet and its majestic rings soon after equinox. Imaged from nearly behind, Saturn and its moon Tethys each show a crescent phase to Cassini that is not visible from Earth. As the rings continue to point nearly toward the Sun, only a thin shadow of Saturn's rings is visible across the center of the planet. Close inspection of Saturn's rings, however, shows superposed bright features identified as spokes that are thought to be groups of very small electrically charged ice particles. Understanding the nature and dynamics of spokes is not fully understood and remains a topic of resear Quote
wez Posted November 11, 2009 Author Posted November 11, 2009 Great Observatories Explore Galactic Center Credit: NASA, ESA, SSC, CXC, and STScI [attach=full]1903[/attach] Explanation: Where can a telescope take you? Four hundred years ago, a telescope took Galileo to the Moon to discover craters, to Saturn to discover rings, to Jupiter to discover moons, to Venus to discover phases, and to the Sun to discover spots. Today, in celebration of Galileo's telescopic achievements and as part of the International Year of Astronomy, NASA has used its entire fleet of Great Observatories, and the Internet, to bring the center of our Galaxy to you. Pictured above, in greater detail and in more colors than ever seen before, are the combined images of the Hubble Space Telescope in optical light, the Spitzer Space Telescope in infrared light, and the Chandra X-ray Observatory in X-ray light. A menagerie of vast star fields is visible, along with dense star clusters, long filaments of gas and dust, expanding supernova remnants, and the energetic surroundings of what likely is our Galaxy's central black hole. Many of these features are labeled on a complementary annotated image. Of course, a telescope's magnification and light-gathering ability create only an image of what a human could see if visiting these places. To actually go requires rockets. Quote
wez Posted November 13, 2009 Author Posted November 13, 2009 Art and Science in NGC 918 Credit & Copyright: Joseph Brimacombe [attach=full]1904[/attach] Explanation: This beautiful telescopic skyscape features spiral galaxy NGC 918. The island universe is about 50,000 light-years across and lies some 60 million light-years away toward the constellation Aries. An artistic presentation, the image shows spiky foreground stars in our own Milky Way Galaxy and convoluted dust clouds that hang hundreds of light-years above our galactic plane, dimly reflecting starlight. It also captures NGC 918 in a cosmic moment important to astrophysicists on planet Earth. Light from supernova SN2009js, absent in previous images, is indicated by the two lines just below and left of the galaxy's center. The supernova itself is the death explosion of a massive star within the plane of galaxy NGC 918. It was just discovered in October by supernova search teams in Japan and the US. Quote
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