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Cartwheel Galaxy Makes Waves
| Title |
Cartwheel Galaxy Makes Waves |
| Description |
This false-color composite image shows the Cartwheel galaxy as seen by the Galaxy Evolution Explorer's Far Ultraviolet detector (blue), the Hubble Space Telescope's Wide Field and Planetary Camera-2 in B-band visible light (green), the Spitzer Space Telescope's Infrared Array Camera (IRAC) at 8 microns (red), and the Chandra X-ray Observatory's Advanced CCD Imaging Spectrometer-S array instrument (purple). Approximately 100 million years ago, a smaller galaxy plunged through the heart of Cartwheel galaxy, creating ripples of brief star formation. In this image, the first ripple appears as an ultraviolet-bright blue outer ring. The blue outer ring is so powerful in the GALEX observations that it indicates the Cartwheel is one of the most powerful UV-emitting galaxies in the nearby universe. The blue color reveals to astronomers that associations of stars 5 to 20 times as massive as our sun are forming in this region. The clumps of pink along the outer blue ring are regions where both X-rays and UV radiation are superimposed in the image. These X-ray point sources are very likely collections of binary star systems containing a blackhole (called Massive X-ray Binary Systems). The X-ray sources seem to cluster around optical/UV bright supermassive star clusters. The yellow-orange inner ring and nucleus at the center of the galaxy result from the combination of visible and infrared light, which is stronger towards the center. This region of the galaxy represents the second ripple, or ring wave, created in the collision, but has much less star for mation activity than the first (outer) ring wave. The wisps of red spread throughout the interior of the galaxy are organic molecules that have been illuminated by nearby low-level star formation. Meanwhile, the tints of green are less massive, older visible light stars. Although astronomers have not identified exactly which galaxy collided with the Cartwheel, two of three candidate galaxies can be seen in this image to the bottom left of the ring, one as a neon blob and the other as a green spiral. Previously, scientists believed the ring marked the outermost edge of the galaxy, but the latest GALEX observations detect a faint disk, not visible in this image, that extends to twice the diameter of the ring. |
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Older Galaxy Pair Has Surpri
…
| Title |
Older Galaxy Pair Has Surprisingly Youthful Glow |
| Description |
A pair of interacting galaxies might be experiencing the galactic equivalent of a mid-life crisis. For some reason, the pair, called Arp 82, didn't make their stars early on as is typical of most galaxies. Instead, they got a second wind later in life -- about 2 billion years ago -- and started pumping out waves of new stars as if they were young again. Arp 82 is an interacting pair of galaxies with a strong bridge and a long tail. NGC 2535 is the big galaxy and NGC 2536 is its smaller companion. The disk of the main galaxy looks like an eye, with a bright "pupil" in the center and oval-shaped "eyelids." Dramatic "beads on a string" features are visible as chains of evenly spaced star-formation complexes along the eyelids. These are presumably the result of large-scale gaseous shocks from a grazing encounter. The colors of this galaxy indicate that the observed stars are young to intermediate in age, around 2 million to 2 billion years old, much less than the age of the universe (13.7 billion years). The puzzle is: why didn't Arp 82 form many stars earlier, like most galaxies of that mass range? Scientifically, it is an oddball and provides a relatively nearby lab for studying the age of intermediate-mass galaxies. This picture is a composite captured by Spitzer's infrared array camera with light at wavelength 8 microns shown in red, NASA's Galaxy Evolution Explorer combined 1530 and 2310 Angstroms shown in blue, and the Southeastern Association for Research in Astronomy Observatory light at 6940 Angstroms shown in green. |
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Amazing Andromeda Galaxy
| Title |
Amazing Andromeda Galaxy |
| Description |
The many "personalities" of our great galactic neighbor, the Andromeda galaxy, are exposed in this new composite image from NASA's Galaxy Evolution Explorer and the Spitzer Space Telescope. The wide, ultraviolet eyes of Galaxy Evolution Explorer reveal Andromeda's "fiery" nature -- hotter regions brimming with young and old stars. In contrast, Spitzer's super-sensitive infrared eyes show Andromeda's relatively "cool" side, which includes embryonic stars hidden in their dusty cocoons. Galaxy Evolution Explorer detected young, hot, high-mass stars, which are represented in blue, while populations of relatively older stars are shown as green dots. The bright yellow spot at the galaxy's center depicts a particularly dense population of old stars. Swaths of red in the galaxy's disk indicate areas where Spitzer found cool, dusty regions where stars are forming. These stars are still shrouded by the cosmic clouds of dust and gas that collapsed to form them. Together, Galaxy Evolution Explorer and Spitzer complete the picture of Andromeda's swirling spiral arms. Hints of pinkish purple depict regions where the galaxy's populations of hot, high-mass stars and cooler, dust-enshrouded stars co-exist. Located 2.5 million light-years away, the Andromeda is our largest nearby galactic neighbor. The galaxy's entire disk spans about 260,000 light-years, which means that a light beam would take 260,000 years to travel from one end of the galaxy to the other. By comparison, our Milky Way galaxy's disk is about 100,000 light-years across. This image is a false color composite comprised of data from Galaxy Evolution Explorer's far-ultraviolet detector (blue), near-ultraviolet detector (green), and Spitzer's multiband imaging photometer at 24 microns (red). |
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Multiwavelength M81
| Title |
Multiwavelength M81 |
| Description |
This beautiful galaxy is tilted at an oblique angle on to our line of sight, giving a "birds-eye view" of the spiral structure. The galaxy is similar to our Milky Way, but our favorable view provides a better picture of the typical architecture of spiral galaxies. M81 may be undergoing a surge of star formation along the spiral arms due to a close encounter it may have had with its nearby spiral galaxy NGC 3077 and a nearby starburst galaxy (M82) about 300 million years ago. M81 is one of the brightest galaxies that can be seen from the Earth. It is high in the northern sky in the circumpolar constellation Ursa Major, the Great Bear. At an apparent magnitude of 6.8 it is just at the limit of naked-eye visibility. The galaxy's angular size is about the same as that of the Full Moon. This image combines data from the Hubble Space Telescope, the Spitzer Space Telescope, and the Galaxy Evolution Explorer (GALEX) missions. The GALEX ultraviolet data were from the far-UV portion of the spectrum (135 to 175 nanometers). The Spitzer infrared data were taken with the IRAC 4 detector (8 microns). The Hubble data were taken at the blue portion of the spectrum. |
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5-Panel version of Chandra,
…
| Name |
5-Panel version of Chandra, GALEX, Spitzer & Hubble Images |
|
Hubble Photographs Grand Des
…
| Title |
Hubble Photographs Grand Design Spiral Galaxy M81 |
| General Information |
What is Hubble Heritage? A monthly showcase of new and archival Hubble images. Go to the Heritage site. What is an American Astronomical Society Meeting release? A major news announcement issued at an American Astronomical Society meeting, the premier astronomy conference. The sharpest image ever taken of the large "grand design" spiral galaxy M81 is being released today at the American Astronomical Society Meeting in Honolulu, Hawaii. A spiral-shaped system of stars, dust, and gas clouds, the galaxy's arms wind all the way down into the nucleus. Though the galaxy is located 11.6 million light-years away, the Hubble Space Telescope's view is so sharp that it can resolve individual stars, along with open star clusters, globular star clusters, and even glowing regions of fluorescent gas. The Hubble data was taken with the Advanced Camera for Surveys in 2004 through 2006. This color composite was assembled from images taken in blue, visible, and infrared light. |
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The Tail of a Wonderful Star
| Title |
The Tail of a Wonderful Star |
| Explanation |
To seventeenth century [ http://www.seds.org/~spider/spider/Vars/Add/ var-dis.html ] astronomers, Omicron Ceti or Mira was known [ http://www.aavso.org/vstar/vsots/mirahistory.shtml ] as a wonderful star, a star whose brightness could change dramatically in the course of about 11 months. Mira is [ http://www.seds.org/~spider/spider/Vars/mira.html ] now seen as the archetype of an entire class of long-period variable stars. Surprisingly, modern astronomers have only recently discovered another striking characteristic of Mira -- an enormous comet-like tail nearly 13 light-years long. The discovery [ http://www.galex.caltech.edu/MEDIA/2007-04/ ] was made using ultraviolet image data from the Galaxy Evolution Explorer (GALEX [ http://www.galex.caltech.edu/ ]) satellite. Billions of years ago Mira was likely similar to our Sun, but has now become a swollen [ http://antwrp.gsfc.nasa.gov/apod/ap060722.html ] red giant star, its outer layers of material blowing off into interstellar space. Fluorescing in ultraviolet light, the cast off material trails behind the giant star as it [ http://www.galex.caltech.edu/MEDIA/2007-04/images.html#fig5 ] plows through the surrounding interstellar medium at 130 kilometers per "second". The amount of material in Mira's tail is estimated to be equivalent to 3,000 times the mass of planet Earth. About 400 light-years away toward the constellation Cetus, Mira is presently too faint to be seen by the unaided eye, but will become visible again [ http://antwrp.gsfc.nasa.gov/apod/ap070221.html ] in mid-November. |
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The Andromeda Galaxy from GA
…
| Title |
The Andromeda Galaxy from GALEX |
| Explanation |
Why does the Andromeda Galaxy have a giant ring? Viewed in ultraviolet light [ http://imagers.gsfc.nasa.gov/ems/uv.html ], the closest major galaxy to our Milky Way Galaxy [ http://www.seds.org/messier/more/mw.html ] looks more like a ring galaxy [ http://antwrp.gsfc.nasa.gov/apod/ap020909.html ] than a spiral [ http://antwrp.gsfc.nasa.gov/apod/ap030911.html ]. The ring is highlighted beautifully in this newly released image mosaic of Andromeda [ http://antwrp.gsfc.nasa.gov/apod/ap021021.html ] (M31) taken by the GALaxy Evolution Explorer [ http://www.galex.caltech.edu/ABOUT/about.html ] (GALEX), a satellite launched into Earth orbit in April. In the above image [ http://www.galex.caltech.edu/popups/gallery-M31.html ], ultraviolet colors have been digitally shifted to the visual. Young blue stars [ http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1964ApJS....9...65V ] dominate the image, indicating the star forming ring [ http://antwrp.gsfc.nasa.gov/apod/ap010612.html ] as well as other star forming regions even further from the galactic center [ http://antwrp.gsfc.nasa.gov/apod/ap000121.html ]. The origin of the huge 150,000-light year [ http://chandra.harvard.edu/photo/cosmic_distance.html ] ring is unknown but likely related to gravitational interactions [ http://antwrp.gsfc.nasa.gov/apod/ap020506.html ] with small satellite galaxies [ http://antwrp.gsfc.nasa.gov/apod/ap021202.html ] that orbit near the galactic giant. M31 [ http://www.seds.org/messier/m/m031.html ] lies about three million light-years distant and is bright enough to be seen without binoculars toward the constellation [ http://en2.wikipedia.org/wiki/Constellations ] of Andromeda [ http://www.astronomical.org/constellations/and.html ]. |
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Artist's concept of Galaxy E
…
| Title |
Artist's concept of Galaxy Evolution Explorer |
| Description |
Artist's concept of Galaxy Evolution Explorer |
| Date |
12.21.2002 |
|
New Galaxy Quest Readies for
…
| Title |
New Galaxy Quest Readies for Launch |
| Description |
In the Multi-Payload Processing Facility, workers check the deployment of the cover of the telescope on the GALEX satellite. The Galaxy Evolution Explorer (GALEX) is an orbiting space telescope that will observe galaxies in ultraviolet light across 10 billion years of cosmic history. Led by the California Institute of Technology, GALEX will conduct several first-of-a-kind sky surveys, including an extra-galactic (beyond our galaxy) ultraviolet all-sky survey. During its 29-month mission GALEX will produce the first comprehensive map of a Universe of galaxies under construction, bringing more understanding of how galaxies like the Milky Way were formed. GALEX is due to be launched from Cape Canaveral Air Force Station March 25 via a Pegasus rocket. |
| Date |
03.19.2003 |
|
Scene of Multiple Explosions
PIA09220
Far-ultraviolet Detector, Ne
…
| Title |
Scene of Multiple Explosions |
| Original Caption Released with Image |
This composite image shows Z Camelopardalis, or Z Cam, a double-star system featuring a collapsed, dead star, called a white dwarf, and a companion star, as well as a ghostly shell around the system. The massive shell provides evidence of lingering material ejected during and swept up by a powerful classical nova explosion that occurred probably a few thousand years ago. The image combines data gathered from the far-ultraviolet and near-ultraviolet detectors on NASA's Galaxy Evolution Explorer on Jan. 25, 2004. The orbiting observatory first began imaging Z Cam in 2003. Z Cam is the largest white object in the image, located near the center. Parts of the shell are seen as a lobe-like, wispy, yellowish feature below and to the right of Z Cam, and as two large, whitish, perpendicular lines on the left. Z Cam was one of the first known recurrent dwarf nova, meaning it erupts in a series of small, "hiccup-like" blasts, unlike classical novae, which undergo a massive explosion. That's why the huge shell around Z Cam caught the eye of astronomer Dr. Mark Seibert of Carnegie Institution of Washington in Pasadena, Calif. - it could only be explained as the remnant of a full-blown classical nova explosion. This finding provides the first evidence that some binary systems undergo both types of explosions. Previously, a link between the two types of novae had been predicted, but there was no evidence to support the theory. The faint bluish streak in the bottom right corner of the image is ultraviolet light reflected by dust that may or may not be related to Z Cam. Numerous foreground and background stars and galaxies are visible as yellow and white spots. The yellow objects are strong near-ultraviolet emitters, blue features have strong far-ultraviolet emission, and white objects have nearly equal amounts of near-ultraviolet and far-ultraviolet emission. |
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Scene of Multiple Explosions
PIA09220
Far-ultraviolet Detector, Ne
…
| Title |
Scene of Multiple Explosions |
| Original Caption Released with Image |
This composite image shows Z Camelopardalis, or Z Cam, a double-star system featuring a collapsed, dead star, called a white dwarf, and a companion star, as well as a ghostly shell around the system. The massive shell provides evidence of lingering material ejected during and swept up by a powerful classical nova explosion that occurred probably a few thousand years ago. The image combines data gathered from the far-ultraviolet and near-ultraviolet detectors on NASA's Galaxy Evolution Explorer on Jan. 25, 2004. The orbiting observatory first began imaging Z Cam in 2003. Z Cam is the largest white object in the image, located near the center. Parts of the shell are seen as a lobe-like, wispy, yellowish feature below and to the right of Z Cam, and as two large, whitish, perpendicular lines on the left. Z Cam was one of the first known recurrent dwarf nova, meaning it erupts in a series of small, "hiccup-like" blasts, unlike classical novae, which undergo a massive explosion. That's why the huge shell around Z Cam caught the eye of astronomer Dr. Mark Seibert of Carnegie Institution of Washington in Pasadena, Calif. - it could only be explained as the remnant of a full-blown classical nova explosion. This finding provides the first evidence that some binary systems undergo both types of explosions. Previously, a link between the two types of novae had been predicted, but there was no evidence to support the theory. The faint bluish streak in the bottom right corner of the image is ultraviolet light reflected by dust that may or may not be related to Z Cam. Numerous foreground and background stars and galaxies are visible as yellow and white spots. The yellow objects are strong near-ultraviolet emitters, blue features have strong far-ultraviolet emission, and white objects have nearly equal amounts of near-ultraviolet and far-ultraviolet emission. |
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Scene of Multiple Explosions
PIA09220
Far-ultraviolet Detector, Ne
…
| Title |
Scene of Multiple Explosions |
| Original Caption Released with Image |
This composite image shows Z Camelopardalis, or Z Cam, a double-star system featuring a collapsed, dead star, called a white dwarf, and a companion star, as well as a ghostly shell around the system. The massive shell provides evidence of lingering material ejected during and swept up by a powerful classical nova explosion that occurred probably a few thousand years ago. The image combines data gathered from the far-ultraviolet and near-ultraviolet detectors on NASA's Galaxy Evolution Explorer on Jan. 25, 2004. The orbiting observatory first began imaging Z Cam in 2003. Z Cam is the largest white object in the image, located near the center. Parts of the shell are seen as a lobe-like, wispy, yellowish feature below and to the right of Z Cam, and as two large, whitish, perpendicular lines on the left. Z Cam was one of the first known recurrent dwarf nova, meaning it erupts in a series of small, "hiccup-like" blasts, unlike classical novae, which undergo a massive explosion. That's why the huge shell around Z Cam caught the eye of astronomer Dr. Mark Seibert of Carnegie Institution of Washington in Pasadena, Calif. - it could only be explained as the remnant of a full-blown classical nova explosion. This finding provides the first evidence that some binary systems undergo both types of explosions. Previously, a link between the two types of novae had been predicted, but there was no evidence to support the theory. The faint bluish streak in the bottom right corner of the image is ultraviolet light reflected by dust that may or may not be related to Z Cam. Numerous foreground and background stars and galaxies are visible as yellow and white spots. The yellow objects are strong near-ultraviolet emitters, blue features have strong far-ultraviolet emission, and white objects have nearly equal amounts of near-ultraviolet and far-ultraviolet emission. |
|
Ghostly Remnant of an Explos
…
PIA09219
Far-ultraviolet Detector
| Title |
Ghostly Remnant of an Explosive Past |
| Original Caption Released with Image |
This enhanced image from the far-ultraviolet detector on NASA's Galaxy Evolution Explorer shows a ghostly shell of ionized gas around Z Camelopardalis, a binary, or double-star system featuring a collapsed, dead star known as a white dwarf, and a companion star. The image was processed to enhance the diffuse emissions from the shell. Z Cam is the bright object near the center of the image. Parts of the shell are seen as a lobe-like, light-blue feature below and to the right of Z Cam, and as two large, light blue, perpendicular lines on the left. The massive shell around Z Cam provides evidence of material ejected during and swept up by a powerful nova eruption, called a classical nova, which likely occurred a few thousand years ago. In exploding binary systems, one of the two stars steals material from the other until it builds up to a certain level, at that point, the system erupts in a giant inferno. In the case of Z Cam, the white dwarf is pilfering material from its sedate companion. There are two classes of exploding binary star systems, or cataclysmic variables: recurrent dwarf novae, which erupt in small, "hiccup-like" blasts episodically, and classical novae, which undergo huge explosions thousands of times more powerful than dwarf novae. Z Cam was the one of the first known recurrent dwarf novae. Yet the shell of ionized gas around Z Cam detected by the Galaxy Evolution Explorer can only be explained as the remnant of a full-blown classical nova explosion. The discovery of the shell provides the first evidence that some binary systems undergo both types of explosions. Previously, a link between the two types of novae had been predicted, but there was no evidence to support the theory. The Galaxy Evolution Explorer first began imaging Z Cam in 2003, this image was taken on Jan. 25, 2004. The type of emission found around Z Cam is most easily visible at far-ultraviolet wavelengths. Most of the background galaxies and stars have been eliminated by the image processing, although a few linger as white spots near the top. The light-blue streaky clump in the bottom right corner is created by ultraviolet light reflected by dust. It is uncertain if Z Cam is the source of the dust-scattered light. |
|
Ghostly Remnant of an Explos
…
PIA09219
Far-ultraviolet Detector
| Title |
Ghostly Remnant of an Explosive Past |
| Original Caption Released with Image |
This enhanced image from the far-ultraviolet detector on NASA's Galaxy Evolution Explorer shows a ghostly shell of ionized gas around Z Camelopardalis, a binary, or double-star system featuring a collapsed, dead star known as a white dwarf, and a companion star. The image was processed to enhance the diffuse emissions from the shell. Z Cam is the bright object near the center of the image. Parts of the shell are seen as a lobe-like, light-blue feature below and to the right of Z Cam, and as two large, light blue, perpendicular lines on the left. The massive shell around Z Cam provides evidence of material ejected during and swept up by a powerful nova eruption, called a classical nova, which likely occurred a few thousand years ago. In exploding binary systems, one of the two stars steals material from the other until it builds up to a certain level, at that point, the system erupts in a giant inferno. In the case of Z Cam, the white dwarf is pilfering material from its sedate companion. There are two classes of exploding binary star systems, or cataclysmic variables: recurrent dwarf novae, which erupt in small, "hiccup-like" blasts episodically, and classical novae, which undergo huge explosions thousands of times more powerful than dwarf novae. Z Cam was the one of the first known recurrent dwarf novae. Yet the shell of ionized gas around Z Cam detected by the Galaxy Evolution Explorer can only be explained as the remnant of a full-blown classical nova explosion. The discovery of the shell provides the first evidence that some binary systems undergo both types of explosions. Previously, a link between the two types of novae had been predicted, but there was no evidence to support the theory. The Galaxy Evolution Explorer first began imaging Z Cam in 2003, this image was taken on Jan. 25, 2004. The type of emission found around Z Cam is most easily visible at far-ultraviolet wavelengths. Most of the background galaxies and stars have been eliminated by the image processing, although a few linger as white spots near the top. The light-blue streaky clump in the bottom right corner is created by ultraviolet light reflected by dust. It is uncertain if Z Cam is the source of the dust-scattered light. |
|
Ghostly Remnant of an Explos
…
PIA09219
Far-ultraviolet Detector
| Title |
Ghostly Remnant of an Explosive Past |
| Original Caption Released with Image |
This enhanced image from the far-ultraviolet detector on NASA's Galaxy Evolution Explorer shows a ghostly shell of ionized gas around Z Camelopardalis, a binary, or double-star system featuring a collapsed, dead star known as a white dwarf, and a companion star. The image was processed to enhance the diffuse emissions from the shell. Z Cam is the bright object near the center of the image. Parts of the shell are seen as a lobe-like, light-blue feature below and to the right of Z Cam, and as two large, light blue, perpendicular lines on the left. The massive shell around Z Cam provides evidence of material ejected during and swept up by a powerful nova eruption, called a classical nova, which likely occurred a few thousand years ago. In exploding binary systems, one of the two stars steals material from the other until it builds up to a certain level, at that point, the system erupts in a giant inferno. In the case of Z Cam, the white dwarf is pilfering material from its sedate companion. There are two classes of exploding binary star systems, or cataclysmic variables: recurrent dwarf novae, which erupt in small, "hiccup-like" blasts episodically, and classical novae, which undergo huge explosions thousands of times more powerful than dwarf novae. Z Cam was the one of the first known recurrent dwarf novae. Yet the shell of ionized gas around Z Cam detected by the Galaxy Evolution Explorer can only be explained as the remnant of a full-blown classical nova explosion. The discovery of the shell provides the first evidence that some binary systems undergo both types of explosions. Previously, a link between the two types of novae had been predicted, but there was no evidence to support the theory. The Galaxy Evolution Explorer first began imaging Z Cam in 2003, this image was taken on Jan. 25, 2004. The type of emission found around Z Cam is most easily visible at far-ultraviolet wavelengths. Most of the background galaxies and stars have been eliminated by the image processing, although a few linger as white spots near the top. The light-blue streaky clump in the bottom right corner is created by ultraviolet light reflected by dust. It is uncertain if Z Cam is the source of the dust-scattered light. |
|
Ghostly Remnant of an Explos
…
PIA09219
Far-ultraviolet Detector
| Title |
Ghostly Remnant of an Explosive Past |
| Original Caption Released with Image |
This enhanced image from the far-ultraviolet detector on NASA's Galaxy Evolution Explorer shows a ghostly shell of ionized gas around Z Camelopardalis, a binary, or double-star system featuring a collapsed, dead star known as a white dwarf, and a companion star. The image was processed to enhance the diffuse emissions from the shell. Z Cam is the bright object near the center of the image. Parts of the shell are seen as a lobe-like, light-blue feature below and to the right of Z Cam, and as two large, light blue, perpendicular lines on the left. The massive shell around Z Cam provides evidence of material ejected during and swept up by a powerful nova eruption, called a classical nova, which likely occurred a few thousand years ago. In exploding binary systems, one of the two stars steals material from the other until it builds up to a certain level, at that point, the system erupts in a giant inferno. In the case of Z Cam, the white dwarf is pilfering material from its sedate companion. There are two classes of exploding binary star systems, or cataclysmic variables: recurrent dwarf novae, which erupt in small, "hiccup-like" blasts episodically, and classical novae, which undergo huge explosions thousands of times more powerful than dwarf novae. Z Cam was the one of the first known recurrent dwarf novae. Yet the shell of ionized gas around Z Cam detected by the Galaxy Evolution Explorer can only be explained as the remnant of a full-blown classical nova explosion. The discovery of the shell provides the first evidence that some binary systems undergo both types of explosions. Previously, a link between the two types of novae had been predicted, but there was no evidence to support the theory. The Galaxy Evolution Explorer first began imaging Z Cam in 2003, this image was taken on Jan. 25, 2004. The type of emission found around Z Cam is most easily visible at far-ultraviolet wavelengths. Most of the background galaxies and stars have been eliminated by the image processing, although a few linger as white spots near the top. The light-blue streaky clump in the bottom right corner is created by ultraviolet light reflected by dust. It is uncertain if Z Cam is the source of the dust-scattered light. |
|
Hello to Arms
PIA03536
Ultraviolet/Visible Camera
| Title |
Hello to Arms |
| Original Caption Released with Image |
This image highlights the hidden spiral arms (blue) that were discovered around the nearby galaxy NGC 4625 by the ultraviolet eyes of NASA's Galaxy Evolution Explorer. The image is composed of ultraviolet and visible-light data, from the Galaxy Evolution Explorer and the California Institute of Technology's Digitized Sky Survey, respectively. Near-ultraviolet light is colored green, far-ultraviolet light is colored blue, and optical light is colored red. As the image demonstrates, the lengthy spiral arms are nearly invisible when viewed in optical light while bright in ultraviolet. This is because they are bustling with hot, newborn stars that radiate primarily ultraviolet light. The youthful arms are also very long, stretching out to a distance four times the size of the galaxy's core. They are part of the largest ultraviolet galactic disk discovered so far. Located 31 million light-years away in the constellation Canes Venatici, NGC 4625 is the closest galaxy ever seen with such a young halo of arms. It is slightly smaller than our Milky Way, both in size and mass. However, the fact that this galaxy's disk is forming stars very actively suggests that it might evolve into a more massive and mature galaxy resembling our own. The armless companion galaxy seen below NGC 4625 is called NGC 4618. Astronomers do not know why it lacks arms but speculate that it may have triggered the development of arms in NGC 4625. |
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GALEX 1st Light Near Ultravi
…
PIA04278
GALEX Telescope
| Title |
GALEX 1st Light Near Ultraviolet -50 |
| Original Caption Released with Image |
This image was taken May 21 and 22 by NASA's Galaxy Evolution Explorer. The image was made from data gathered by the two channels of the spacecraft camera during the mission's "first light" milestone. It shows about 50 celestial objects in the constellation Hercules. The reddish objects represent those detected by the camera's near ultraviolet channel over a 5-minute period, while bluish objects were detected over a 3-minute period by the camera's far ultraviolet channel. Deeper imaging may confirm the apparent existence in this field of galaxy pairs and triplets or individual star formation regions in single galaxies. The Galaxy Evolution Explorer's first light images are dedicated to the crew of the Space Shuttle Columbia. The Hercules region was directly above Columbia when it made its last contact with NASA Mission Control on February 1, over the skies of Texas. The Galaxy Evolution Explorer launched on April 28 on a mission to map the celestial sky in the ultraviolet and determine the history of star formation in the universe over the last 10 billion years. |
|
GALEX 1st Light Near Ultravi
…
PIA04279
GALEX Telescope
| Title |
GALEX 1st Light Near Ultraviolet |
| Original Caption Released with Image |
This image was taken on May 21 and 22 by NASA's Galaxy Evolution Explorer. The image was made from data gathered during the missions "first light" milestone, and shows celestial objects in the constellation Hercules. The objects shown represent those detected by the camera's near ultraviolet channel over a 5-minute period. The radial streaks at the edge of the image are due to stars reflecting from the near ultraviolet detector window. The Galaxy Evolution Explorer's first light images are dedicated to the crew of the Space Shuttle Columbia. The Hercules region was directly above Columbia when it made its last contact with NASA Mission Control on February 1, over the skies of Texas. The Galaxy Evolution Explorer launched on April 28 on a mission to map the celestial sky in the ultraviolet and determine the history of star formation in the universe over the last 10 billion years. |
|
GALEX 1st Light Compilation
PIA04282
GALEX Telescope
| Title |
GALEX 1st Light Compilation |
| Original Caption Released with Image |
This compilation shows the constellation Hercules, as imaged on May 21 and 22 by NASA's Galaxy Evolution Explorer. The images were captured by the two channels of the spacecraft camera during the mission's "first light" milestone. The Galaxy Evolution Explorer first light images are dedicated to the crew of the Space Shuttle Columbia. The Hercules region was directly above Columbia when it made its last contact with NASA Mission Control on February 1, over the skies of Texas. The Galaxy Evolution Explorer launched on April 28 on a mission to map the celestial sky in the ultraviolet and determine the history of star formation in the universe over the last 10 billion years. |
|
GALEX 1st Light Far Ultravio
…
PIA04280
GALEX Telescope
| Title |
GALEX 1st Light Far Ultraviolet |
| Original Caption Released with Image |
This image was taken May 21 and 22 by NASA's Galaxy Evolution Explorer. The image was made from data gathered by the far ultraviolet channel of the spacecraft camera during the mission's "first light" milestone. It shows about 400 celestial objects, appearing in blue, detected over a 3-minute, 20-second period in the constellation Hercules. The Galaxy Evolution Explorer's first light images are dedicated to the crew of the Space Shuttle Columbia. The Hercules region was directly above Columbia when it made its last contact with NASA Mission Control on February 1, over the skies of Texas. The Galaxy Evolution Explorer launched on April 28 on a mission to map the celestial sky in the ultraviolet and determine the history of star formation in the universe over the last 10 billion years. |
|
GALEX 1st Light Near and Far
…
PIA04281
GALEX Telescope
| Title |
GALEX 1st Light Near and Far Ultraviolet -100 |
| Original Caption Released with Image |
NASA's Galaxy Evolution Explorer took this image on May 21 and 22. The image was made from data gathered by the two channels of the spacecraft camera during the mission's "first light" milestone. It shows about 100 celestial objects in the constellation Hercules. The reddish objects represent those detected by the camera's near ultraviolet channel over a 5-minute period, while bluish objects were detected over a 3-minute period by the camera's far ultraviolet channel. The Galaxy Evolution Explorer's first light images are dedicated to the crew of the Space Shuttle Columbia. The Hercules region was directly above Columbia when it made its last contact with NASA Mission Control on February 1, over the skies of Texas. The Galaxy Evolution Explorer launched on April 28 on a mission to map the celestial sky in the ultraviolet and determine the history of star formation in the universe over the last 10 billion years. |
|
Galaxy Evolution Explorer Sp
…
PIA09653
Far-ultraviolet Detector, Ne
…
| Title |
Galaxy Evolution Explorer Spies Band of Stars |
| Original Caption Released with Image |
The Galaxy Evolution Explorer's ultraviolet eyes have captured a globular star cluster, called NGC 362, in our own Milky Way galaxy. In this new image, the cluster appears next to stars from a more distant neighboring galaxy, known as the Small Magellanic Cloud. Globular clusters are densely packed bunches of old stars scattered in galaxies throughout the universe. NGC 362, located 30,000 light-years away, can be spotted as the dense collection of mostly yellow-tinted stars surrounding a large white-yellow spot toward the top-right of this image. The white spot is actually the core of the cluster, which is made up of stars so closely packed together that the Galaxy Evolution Explorer cannot see them individually. The light blue dots surrounding the cluster core are called extreme horizontal branch stars. These stars used to be very similar to our sun and are nearing the end of their lives. They are very hot, with temperatures reaching up to about four times that of the surface of our sun (25,000 Kelvin or 45,500 degrees Fahrenheit). A star like our sun spends most of its life fusing hydrogen atoms in its core into helium. When the star runs out of hydrogen in its core, its outer envelope will expand. The star then becomes a red giant, which burns hydrogen in a shell surrounding its inner core. Throughout its life as a red giant, the star loses a lot of mass, then begins to burn helium at its core. Some stars will have lost so much mass at the end of this process, up to 85 percent of their envelopes, that most of the envelope is gone. What is left is a very hot ultraviolet-bright core, or extreme horizontal branch star. Blue dots scattered throughout the image are hot, young stars in the Small Magellanic Cloud, a satellite galaxy of the Milky Way located approximately 200,000 light-years away. The stars in this galaxy are much brighter intrinsically than extreme horizontal branch stars, but they appear just as bright because they are farther away. The blue stars in the Small Magellanic Cloud are only about a few tens of millions of years old, much younger than the approximately 10-million-year-old stars in NGC 362. Because NGC 362 sits on the northern edge of the Small Magellanic Cloud galaxy, the blue stars are denser toward the south, or bottom, of the image. Some of the yellow spots in this image are stars in the Milky Way galaxy that are along this line of sight. Astronomers believe that some of the other spots, particularly those closer to NGC 362, might actually be a relatively ultraviolet-dim family of stars called "blue stragglers." These stars are formed from collisions or close encounters between two closely orbiting stars in a globular cluster. This image is a false-color composite, where light detected by the Galaxy Evolution Explorer's far-ultraviolet detector is colored blue, and light from the telescope's near-ultraviolet detector is red. |
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GALEX Distributes Local Gala
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PIA03295
GALEX Telescope
| Title |
GALEX Distributes Local Galactic Treasures at AAS |
| Original Caption Released with Image |
GALEX Poster From sparkling blue rings to dazzling golden disks, Galaxy Evolution Explorer (Galex) scientists are handing out a collection of their finest galactic treasures at the January 2006 American Astronomical Society meeting in Washington, D.C. Mined from the mission's Survey of Nearby Galaxies data, these cosmic gems were collected with the telescope's sensitive ultraviolet instruments. The gallery of galaxies has been made into a poster for meeting attendees visiting the mission's booth. Organized from far-ultraviolet to near-ultraviolet bright galaxies, this poster encapsulates the heart of the mission to study how galaxies and star formation rates have changed over the past 10 billion years. Events in space take millions or billions of years to unfold, which means that astronomers can't watch individual galaxies and stars age over time. Luckily, because the physics of light travel dictates that the farther away an object is from Earth, the longer it takes for its light to travel to us, the universe can be thought of as a time machine. By building telescopes sensitive enough to capture objects that are 10 billion light-years away, astronomers can essentially see an object the way it looked 10 billion years ago. Galex astronomers are using this phenomenon to their advantage by taking snapshots of different galaxies at various distances in space. By comparing portraits of numerous objects at various times in the universe's history, the team can begin to piece together the life cycle of stars and galaxies. For the poster, Galex scientists organized 196 different nearby galaxies in bins of increasing ultraviolet color. By placing the various snapshots side by side, astronomers can see how galaxies age differently. When viewed in ultraviolet, active star-forming regions in galaxies can be seen as glittering blue structures, while a soft, golden glow indicates the presence of older stars. The 196 galaxies represented in the poster were selected from more than 1,000 galaxies in the "Ultraviolet Atlas of Nearby Galaxies." So far, the Galex mission has surveyed more than 100 million galaxies. |
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GALEX Distributes Local Gala
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PIA03295
GALEX Telescope
| Title |
GALEX Distributes Local Galactic Treasures at AAS |
| Original Caption Released with Image |
GALEX Poster From sparkling blue rings to dazzling golden disks, Galaxy Evolution Explorer (Galex) scientists are handing out a collection of their finest galactic treasures at the January 2006 American Astronomical Society meeting in Washington, D.C. Mined from the mission's Survey of Nearby Galaxies data, these cosmic gems were collected with the telescope's sensitive ultraviolet instruments. The gallery of galaxies has been made into a poster for meeting attendees visiting the mission's booth. Organized from far-ultraviolet to near-ultraviolet bright galaxies, this poster encapsulates the heart of the mission to study how galaxies and star formation rates have changed over the past 10 billion years. Events in space take millions or billions of years to unfold, which means that astronomers can't watch individual galaxies and stars age over time. Luckily, because the physics of light travel dictates that the farther away an object is from Earth, the longer it takes for its light to travel to us, the universe can be thought of as a time machine. By building telescopes sensitive enough to capture objects that are 10 billion light-years away, astronomers can essentially see an object the way it looked 10 billion years ago. Galex astronomers are using this phenomenon to their advantage by taking snapshots of different galaxies at various distances in space. By comparing portraits of numerous objects at various times in the universe's history, the team can begin to piece together the life cycle of stars and galaxies. For the poster, Galex scientists organized 196 different nearby galaxies in bins of increasing ultraviolet color. By placing the various snapshots side by side, astronomers can see how galaxies age differently. When viewed in ultraviolet, active star-forming regions in galaxies can be seen as glittering blue structures, while a soft, golden glow indicates the presence of older stars. The 196 galaxies represented in the poster were selected from more than 1,000 galaxies in the "Ultraviolet Atlas of Nearby Galaxies." So far, the Galex mission has surveyed more than 100 million galaxies. |
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A Real Shooting Star
PIA09960
Ultraviolet/Visible Camera
| Title |
A Real Shooting Star |
| Original Caption Released with Image |
"" Click on the image for movie of A Real Shooting Star This artist's animation illustrates a star flying through our galaxy at supersonic speeds, leaving a 13-light-year-long trail of glowing material in its wake. The star, named Mira (pronounced my-rah) after the latin word for "wonderful," sheds material that will be recycled into new stars, planets and possibly even life. NASA's Galaxy Evolution Explorer discovered the long trail of material behind Mira during its survey of the entire sky in ultraviolet light. The animation begins by showing a close-up of Mira -- a red-giant star near the end of its life. Red giants are red in color and extremely bloated, for example, if a red giant were to replace our sun, it would engulf everything out to the orbit of Mars. They constantly blow off gas and dust in the form of stellar winds, supplying the galaxy with molecules, such as oxygen and carbon, that will make their way into new solar systems. Our sun will mature into a red giant in about 5 billion years. As the animation pulls out, we can see the enormous trail of material deposited behind Mira as it hurls along between the stars. Like a boat traveling through water, a bow shock, or build up of gas, forms ahead of the star in the direction of its motion. Gas in the bow shock is heated and then mixes with the cool hydrogen gas in the wind that is blowing off Mira. This heated hydrogen gas then flows around behind the star, forming a turbulent wake. Why does the trailing hydrogen gas glow in ultraviolet light? When it is heated, it transitions into a higher-energy state, which then loses energy by emitting ultraviolet light - a process known as fluorescence. Finally, the artist's rendering gives way to the actual ultraviolet image taken by the Galaxy Evolution Explorer Mira is located 350 light-years from Earth in the constellation Cetus, otherwise known as the whale. Coincidentally, Mira and its "whale of a tail" can be found in the tail of the whale constellation. |
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Look at my Arms!
PIA03541
Ultraviolet/Visible Camera
| Title |
Look at my Arms! |
| Original Caption Released with Image |
This image shows the hidden spiral arms that were discovered around the galaxy called NGC 4625 (top) by the ultraviolet eyes of NASA's Galaxy Evolution Explorer. An armless companion galaxy called NGC 4618 is pictured below. Though the lengthy spiral arms are nearly invisible when viewed in optical light, they glow brightly in ultraviolet. This is because they are bustling with hot, newborn stars that radiate primarily ultraviolet light. The youthful arms are also very long, stretching out to a distance four times the size of the galaxy's core. They are part of the largest ultraviolet galactic disk discovered so far. Located 31 million light-years away in the constellation Canes Venatici, NGC 4625 is the closest galaxy ever seen with such a young halo of arms. It is slightly smaller than our Milky Way, both in size and mass. However, the fact that this galaxy's disk is forming stars very actively suggests that it might evolve into a more massive and mature galaxy resembling our own. Astronomers do not know why NGC 4618 lacks arms but speculate that it may have triggered the development of arms in NGC 4625. |
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Galactic Halos of Hydrogen
PIA03540
Ultraviolet/Visible Camera
| Title |
Galactic Halos of Hydrogen |
| Original Caption Released with Image |
This image shows two companion galaxies, NGC 4625 (top) and NGC 4618 (bottom), and their surrounding cocoons of cool hydrogen gas (purple). The huge set of spiral arms on NGC 4625 (blue) was discovered by the ultraviolet eyes of NASA's Galaxy Evolution Explorer. Though these arms are nearly invisible when viewed in optical light, they glow brightly in ultraviolet. This is because they are bustling with hot, newborn stars that radiate primarily ultraviolet light. The vibrant spiral arms are also quite lengthy, stretching out to a distance four times the size of the galaxy's core. They are part of the largest ultraviolet galactic disk discovered so far. Astronomers do not know why NGC 4625 grew arms while NGC 4618 did not. The purple nebulosity shown here illustrates that hydrogen gas - an ingredient of star formation - is diffusely distributed around both galaxies. This means that other unknown factors led to the development of the arms of NGC 4625. Located 31 million light-years away in the constellation Canes Venatici, NGC 4625 is the closest galaxy ever seen with such a young halo of arms. It is slightly smaller than our Milky Way, both in size and mass. However, the fact that this galaxy's disk is forming stars very actively suggests that it might evolve into a more massive and mature galaxy resembling our own. The image is composed of ultraviolet, visible-light and radio data, from the Galaxy Evolution Explorer, the California Institute of Technology's Digitized Sky Survey, and the Westerbork Synthesis Radio Telescope, the Netherlands, respectively. Near-ultraviolet light is colored green, far-ultraviolet light is colored blue, and optical light is colored red. Radio emissions are colored purple. |
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Fires of Galactic Youth (Art
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PIA07144
GALEX Telescope
| Title |
Fires of Galactic Youth (Artist Animation) |
| Original Caption Released with Image |
Figure 1 This artist's animation shows a typical young galaxy, teeming with hot, newborn stars and exploding supernovas. The supernovas are seen as white flashes of light. NASA's Galaxy Evolution Explorer spotted three-dozen young galaxies like the one shown here in our corner of the universe. It was able to see them with the help of its highly sensitive ultraviolet detectors. Because newborn stars radiate ultraviolet light, young galaxies light up brilliantly when viewed in ultraviolet wavelengths. The findings came as a surprise, because astronomers had thought that the universe's "birth-rate" had declined, and that massive galaxies were no longer forming. |
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Fires of Galactic Youth (Art
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PIA07144
GALEX Telescope
| Title |
Fires of Galactic Youth (Artist Animation) |
| Original Caption Released with Image |
Figure 1 This artist's animation shows a typical young galaxy, teeming with hot, newborn stars and exploding supernovas. The supernovas are seen as white flashes of light. NASA's Galaxy Evolution Explorer spotted three-dozen young galaxies like the one shown here in our corner of the universe. It was able to see them with the help of its highly sensitive ultraviolet detectors. Because newborn stars radiate ultraviolet light, young galaxies light up brilliantly when viewed in ultraviolet wavelengths. The findings came as a surprise, because astronomers had thought that the universe's "birth-rate" had declined, and that massive galaxies were no longer forming. |
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Surprise Ultraviolet Party i
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PIA07251
GALEX Telescope
| Title |
Surprise Ultraviolet Party in the Sky |
| Original Caption Released with Image |
Galaxies aren't the only objects filling up the view of NASA's Galaxy Evolution Explorer. Since its launch in 2003, the space telescope -- originally designed to observe galaxies across the universe in ultraviolet light -- has discovered a festive sky blinking with flaring and erupting stars, as well as streaking asteroids, satellites and space debris. A group of six streaking objects -- the identities of which remain unknown -- can be seen here flying across the telescope's sight in this sped-up movie. The two brightest objects appear to perform a sharp turn then travel in the reverse direction. This illusion is most likely the result of the Galaxy Evolution Explorer overtaking the objects as it orbits around Earth. Careful inspection reveals four additional faint objects with the same timing and behavior. These faint objects are easiest to see during the retrograde portion of their paths. Three appear between the two bright sources, and one is above them, near the edge of the field of view. These bonus objects are being collected in to public catalogues for other astronomers to study. |
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It's Not a Bird or a Plane
PIA07250
GALEX Telescope
| Title |
It's Not a Bird or a Plane |
| Original Caption Released with Image |
Galaxies aren't the only objects filling up the view of NASA's Galaxy Evolution Explorer. Since its launch in 2003, the space telescope -- originally designed to observe galaxies across the universe in ultraviolet light -- has discovered a festive sky blinking with flaring and erupting stars, as well as streaking asteroids, satellites and space debris. One such streaking object -- possibly an Earth-orbiting satellite -- can be seen here flying across the telescope's sight in this sped-up movie. This probable satellite appears during the last 5 minutes of a 13.5-minute observation. It looks elongated because each picture frame containing the moving object is 19 seconds long. Faint ghost images on either side of the source are detector artifacts caused by the object's extreme brightness. These bonus objects are being collected in to public catalogues for other astronomers to study. |
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Dwarf Star Erupts in Giant F
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PIA07249
GALEX Telescope
| Title |
Dwarf Star Erupts in Giant Flare |
| Original Caption Released with Image |
This movie taken by NASA'S Galaxy Evolution Explorer shows one of the largest flares, or star eruptions, ever recorded at ultraviolet wavelengths. The star, called GJ 3685A, just happened to be in the Galaxy Evolution Explorer's field of view while the telescope was busy observing galaxies. As the movie demonstrates, the seemingly serene star suddenly exploded once, then even more intensely a second time, pouring out in total about one million times more energy than a typical flare from our Sun. The second blast of light constituted an increase in brightness by a factor of at least 10,000. Flares are huge explosions of energy stemming from a single location on a star's surface. They are caused by the brief destruction of a star's magnetic fields. Many types of stars experience them, though old, small, rapidly rotating "red dwarfs" like GJ 3685A tend to flare more frequently and dramatically. These stars, called flare stars, can experience powerful eruptions as often as every few hours. Younger stars, in general, also erupt more often. One of the reasons astronomers study flare stars is to gain a better picture and history of flare events taking place on the Sun. A preliminary analysis of the GJ 3685A flare shows that the mechanisms underlying stellar eruptions may be more complex than previously believed. Evidence for the two most popular flare theories was found. Though this movie has been sped up (the actual flare lasted about 20 minutes), time-resolved data exist for each one-hundredth of a second. These observations were taken at 2 p.m. Pacific time, April 24, 2004. In the still image, the time sequence starts in the upper left panel, continues in the upper right, then moves to the lower left and ends in the lower right. The circular and linear features that appear below and to the right of GJ 3685A during the flare event are detector artifacts caused by the extreme brightness of the flare. |
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New Galaxy Quest Readies for
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PIA04264
GALEX Telescope
| Title |
New Galaxy Quest Readies for Launch |
| Original Caption Released with Image |
In the Multi-Payload Processing Facility, workers check the deployment of the cover of the telescope on the GALEX satellite. The Galaxy Evolution Explorer (GALEX) is an orbiting space telescope that will observe galaxies in ultraviolet light across 10 billion years of cosmic history. Led by the California Institute of Technology, GALEX will conduct several first-of-a-kind sky surveys, including an extra-galactic (beyond our galaxy) ultraviolet all-sky survey. During its 29-month mission GALEX will produce the first comprehensive map of a Universe of galaxies under construction, bringing more understanding of how galaxies like the Milky Way were formed. GALEX is due to be launched from Cape Canaveral Air Force Station March 25 via a Pegasus rocket. |
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Galaxy Mission Completes Fou
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PIA09337
GALEX Telescope
| Title |
Galaxy Mission Completes Four Star-Studded Years in Space |
| Original Caption Released with Image |
NASA's Galaxy Evolution Explorer is celebrating its fourth year in space with some of M81's "hottest" stars. In a new ultraviolet image, the magnificent M81 spiral galaxy is shown at the center. The orbiting observatory spies the galaxy's "sizzling young starlets" as wisps of bluish-white swirling around a central golden glow. The tints of gold at M81's center come from a "senior citizen" population of smoldering stars. "This is a spectacular view of M81," says Dr. John Huchra, of the Harvard Smithsonian Center for Astrophysics, Cambridge, Mass. "When we proposed to observe this galaxy with GALEX we hoped to see globular clusters, open clusters, and young stars...this view is everything that we were hoping for." The image is one of thousands gathered so far by GALEX, which launched April 28, 2003. This mission uses ultraviolet wavelengths to measure the history of star formation 80 percent of the way back to the Big Bang. The large fluffy bluish-white material to the left of M81 is a neighboring galaxy called Holmberg IX. This galaxy is practically invisible to the naked human eye. However, it is illuminated brilliantly in GALEX's wide ultraviolet eyes. Its ultraviolet colors show that it is actively forming young stars. The bluish-white fuzz in the space surrounding M81 and Holmberg IX is new star formation triggered by gravitational interactions between the two galaxies. Huchra notes that the active star formation in Holmberg IX is a surprise, and says that more research needs to be done in light of the new findings from GALEX. "Some astronomers suspect that the galaxy Holmberg IX is the result of a galactic interaction between M81 and another neighboring galaxy M82," says Huchra. "This particular galaxy is especially important because there are a lot of galaxies like Holmberg IX around our Milky Way galaxy. By understanding how Holmberg IX came to be, we hope to understand how all the little galaxies surrounding the Milky Way developed.""Four years after GALEX's launch, the spacecraft is performing magnificently. The mission results have been simply amazing as it helps us to unlock the secrets of galaxies, the building blocks of our universe," says Kerry Erickson, GALEX project manager. M81 and Holberg IX are located approximately 12 million light-years away in the northern constellation Ursa Major. In addition to leading the GALEX observations of M81, Huchra and his team also took observations of the region with NASA's Spitzer and Hubble space telescopes. By combining all these views of M81, Huchra hopes to gain a better understanding about how M81 has developed into the spiral galaxy we see today. The California Institute of Technology in Pasadena, Calif., leads the Galaxy Evolution Explorer mission and is responsible for science operations and data analysis. NASA's Jet Propulsion Laboratory, also in Pasadena, manages the mission and built the science instrument. The mission was developed under NASA's Explorers Program, managed by the Goddard Space Flight Center, Greenbelt, Md. Researchers from South Korea and France collaborated on this mission. |
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Mira's Tail There All Along
PIA09961
Ultraviolet/Visible Camera
| Title |
Mira's Tail There All Along |
| Original Caption Released with Image |
NASA's Galaxy Evolution Explorer discovered an exceptionally long comet-like tail of material trailing behind Mira -- a star that has been studied thoroughly for about 400 years. So, why had this tail gone unnoticed for so long? The answer is that nobody had scanned the extended region around Mira in ultraviolet light until now. As this composite demonstrates, the tail is only visible in ultraviolet light (top), and does not show up in visible light (bottom). Incidentally, Mira is much brighter in visible than ultraviolet light due to its low surface temperature of about 3,000 kelvin (about 5,000 degrees Fahrenheit). The Galaxy Evolution Explorer, one of NASA's Small Explorer class missions, is the first all-sky survey in ultraviolet light. It found Mira's tail by chance during a routine scan. Since the mission's launch more than four years ago, it has surveyed millions of galaxies and stars. Such vast collections of data often bring welcome surprises, such as Mira's unusual tail. The visible-light image is from the United Kingdom Schmidt Telescope in Australia, via the Digitized Sky Survey, a program affiliated with the Space Telescope Science Institute, Baltimore, Md. |
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Anatomy of a Shooting Star
PIA09959
Ultraviolet/Visible Camera
| Title |
Anatomy of a Shooting Star |
| Original Caption Released with Image |
Annotated Version A close-up view of a star racing through space faster than a speeding bullet can be seen in this image from NASA's Galaxy Evolution Explorer. The star, called Mira (pronounced My-rah), is traveling at 130 kilometers per second, or 291,000 miles per hour. As it hurls along, it sheds material that will be recycled into new stars, planets and possibly even life. In this image, Mira is moving from left to right. It is visible as the pinkish dot in the bulb shape at right. The yellow dot below is a foreground star. Mira is traveling so fast that it's creating a bow shock, or build-up of gas, in front of it, as can be seen here at right. Like a boat traveling through water, a bow shock forms ahead of the star in the direction of its motion. Gas in the bow shock is heated and then mixes with the cool hydrogen gas in the wind that is blowing off Mira. This heated hydrogen gas then flows around behind the star, forming a wake. Why is the wake of material glowing? When the hydrogen gas is heated, it transitions into a higher-energy state, which then loses energy by emitting ultraviolet light - a process called fluorescence. The Galaxy Evolution Explorer has special instruments that can detect this ultraviolet light. A similar fluorescence process is responsible for the Northern Lights -- a glowing, green aurora that can be seen from northern latitudes. However, in that case nitrogen and oxygen gas are fluorescing with visible light. Streams and a loop of material can also be seen coming off Mira. Astronomers are still investigating what these streams are, but they suspect that they are denser parts of Mira's wind perhaps flowing out of the star's poles. This image consists of data captured by both the far- and near-ultraviolet detectors on the Galaxy Evolution Explorer between November 18 and December 15, 2006. It has a total exposure time of about 3 hours. |
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Anatomy of a Shooting Star
PIA09959
Ultraviolet/Visible Camera
| Title |
Anatomy of a Shooting Star |
| Original Caption Released with Image |
Annotated Version A close-up view of a star racing through space faster than a speeding bullet can be seen in this image from NASA's Galaxy Evolution Explorer. The star, called Mira (pronounced My-rah), is traveling at 130 kilometers per second, or 291,000 miles per hour. As it hurls along, it sheds material that will be recycled into new stars, planets and possibly even life. In this image, Mira is moving from left to right. It is visible as the pinkish dot in the bulb shape at right. The yellow dot below is a foreground star. Mira is traveling so fast that it's creating a bow shock, or build-up of gas, in front of it, as can be seen here at right. Like a boat traveling through water, a bow shock forms ahead of the star in the direction of its motion. Gas in the bow shock is heated and then mixes with the cool hydrogen gas in the wind that is blowing off Mira. This heated hydrogen gas then flows around behind the star, forming a wake. Why is the wake of material glowing? When the hydrogen gas is heated, it transitions into a higher-energy state, which then loses energy by emitting ultraviolet light - a process called fluorescence. The Galaxy Evolution Explorer has special instruments that can detect this ultraviolet light. A similar fluorescence process is responsible for the Northern Lights -- a glowing, green aurora that can be seen from northern latitudes. However, in that case nitrogen and oxygen gas are fluorescing with visible light. Streams and a loop of material can also be seen coming off Mira. Astronomers are still investigating what these streams are, but they suspect that they are denser parts of Mira's wind perhaps flowing out of the star's poles. This image consists of data captured by both the far- and near-ultraviolet detectors on the Galaxy Evolution Explorer between November 18 and December 15, 2006. It has a total exposure time of about 3 hours. |
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Mira Soars Through the Sky
PIA09958
Ultraviolet/Visible Camera
| Title |
Mira Soars Through the Sky |
| Original Caption Released with Image |
New ultraviolet images from NASA's Galaxy Evolution Explorer shows a speeding star that is leaving an enormous trail of "seeds" for new solar systems. The star, named Mira (pronounced my-rah) after the latin word for "wonderful," is shedding material that will be recycled into new stars, planets and possibly even life as it hurls through our galaxy. In figure 1, the upper panel shows Mira's full, comet-like tail as seen only in shorter, or "far" ultraviolet wavelengths, while the lower panel is a combined view showing both far and longer, or "near" ultraviolet wavelengths. The close-up picture at bottom gives a better look at Mira itself, which appears as a pinkish dot, and is moving from left to right in this view. Shed material appears in light blue. The dots in the picture are stars and distant galaxies. The large blue dot on the left side of the upper panel, and the large yellow dot in the lower panel, are both stars that are closer to us than Mira. The Galaxy Evolution Explorer discovered the strange tail during part of its routine survey of the entire sky at ultraviolet wavelengths. When astronomers first saw the picture, they were shocked because Mira has been studied for over 400 years yet nothing like this has ever been documented before. Mira's comet-like tail stretches a startling 13 light-years across the sky. For comparison, the nearest star to our sun, Proxima Centauri, is only about 4 light-years away. Mira's tail also tells a tale of its history -- the material making it up has been slowly blown off over time, with the oldest material at the end of the tail being released about 30,000 years ago (figure 2). Mira is a highly evolved, "red giant" star near the end of its life. Technically, it is called an asymptotic giant branch star. It is red in color and bloated, for example, if a red giant were to replace our sun, it would engulf everything out to the orbit of Mars. Our sun will mature into a red giant in about 5 billion years. Like other red giants, Mira will lose a large fraction of its mass in the form of gas and dust. In fact, Mira ejects the equivalent of the Earth's mass every 10 years. It has released enough material over the past 30,000 years to seed at least 3,000 Earth-sized planets or 9 Jupiter-sized ones. While most stars travel along together around the disk of our Milky Way, Mira is charging through it. Because Mira is not moving with the "pack," it is moving much faster relative to the ambient gas in our section of the Milky Way. It is zipping along at 130 kilometers per second, or 291,000 miles per hour, relative to this gas. Mira's breakneck speed together with its outflow of material are responsible for its unique glowing tail. Images from the Galaxy Evolution Explorer show a large build-up of gas, or bow shock, in front of the star, similar to water piling up in front of a speeding boat. Scientists now know that hot gas in this bow shock mixes with the cooler, hydrogen gas being shed from Mira,, causing it to heat up as it swirls back into a turbulent wake. As the hydrogen gas loses energy, it fluoresces with ultraviolet light, which the Galaxy Evolution Explorer can detect. Mira, also known as Mira A, is not alone in its travels through space. It has a distant companion star called Mira B that is thought to be the burnt-out, dead core of a star, called a white dwarf. Mira A and B circle around each other slowly, making one orbit about every 500 years. Astronomers believe that Mira B has no effect on Mira's tail. Mira is also what's called a pulsating variable star. It dims and brightens by a factor of 1,500 every 332 days, and will become bright enough to see with the naked eye in mid-November 2007. Because it was the first variable star with a regular period ever discovered, other stars of this type are often referred to as "Miras." Mira is located 350 light-years from Earth in the constellation Cetus, otherwise known as the whale. Coincidentally, Mira and its "whale of a tail" can be found in the tail of the whale constellation. These images were between November 18 and December 15, 2006. |
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Mira Soars Through the Sky
PIA09958
Ultraviolet/Visible Camera
| Title |
Mira Soars Through the Sky |
| Original Caption Released with Image |
New ultraviolet images from NASA's Galaxy Evolution Explorer shows a speeding star that is leaving an enormous trail of "seeds" for new solar systems. The star, named Mira (pronounced my-rah) after the latin word for "wonderful," is shedding material that will be recycled into new stars, planets and possibly even life as it hurls through our galaxy. In figure 1, the upper panel shows Mira's full, comet-like tail as seen only in shorter, or "far" ultraviolet wavelengths, while the lower panel is a combined view showing both far and longer, or "near" ultraviolet wavelengths. The close-up picture at bottom gives a better look at Mira itself, which appears as a pinkish dot, and is moving from left to right in this view. Shed material appears in light blue. The dots in the picture are stars and distant galaxies. The large blue dot on the left side of the upper panel, and the large yellow dot in the lower panel, are both stars that are closer to us than Mira. The Galaxy Evolution Explorer discovered the strange tail during part of its routine survey of the entire sky at ultraviolet wavelengths. When astronomers first saw the picture, they were shocked because Mira has been studied for over 400 years yet nothing like this has ever been documented before. Mira's comet-like tail stretches a startling 13 light-years across the sky. For comparison, the nearest star to our sun, Proxima Centauri, is only about 4 light-years away. Mira's tail also tells a tale of its history -- the material making it up has been slowly blown off over time, with the oldest material at the end of the tail being released about 30,000 years ago (figure 2). Mira is a highly evolved, "red giant" star near the end of its life. Technically, it is called an asymptotic giant branch star. It is red in color and bloated, for example, if a red giant were to replace our sun, it would engulf everything out to the orbit of Mars. Our sun will mature into a red giant in about 5 billion years. Like other red giants, Mira will lose a large fraction of its mass in the form of gas and dust. In fact, Mira ejects the equivalent of the Earth's mass every 10 years. It has released enough material over the past 30,000 years to seed at least 3,000 Earth-sized planets or 9 Jupiter-sized ones. While most stars travel along together around the disk of our Milky Way, Mira is charging through it. Because Mira is not moving with the "pack," it is moving much faster relative to the ambient gas in our section of the Milky Way. It is zipping along at 130 kilometers per second, or 291,000 miles per hour, relative to this gas. Mira's breakneck speed together with its outflow of material are responsible for its unique glowing tail. Images from the Galaxy Evolution Explorer show a large build-up of gas, or bow shock, in front of the star, similar to water piling up in front of a speeding boat. Scientists now know that hot gas in this bow shock mixes with the cooler, hydrogen gas being shed from Mira,, causing it to heat up as it swirls back into a turbulent wake. As the hydrogen gas loses energy, it fluoresces with ultraviolet light, which the Galaxy Evolution Explorer can detect. Mira, also known as Mira A, is not alone in its travels through space. It has a distant companion star called Mira B that is thought to be the burnt-out, dead core of a star, called a white dwarf. Mira A and B circle around each other slowly, making one orbit about every 500 years. Astronomers believe that Mira B has no effect on Mira's tail. Mira is also what's called a pulsating variable star. It dims and brightens by a factor of 1,500 every 332 days, and will become bright enough to see with the naked eye in mid-November 2007. Because it was the first variable star with a regular period ever discovered, other stars of this type are often referred to as "Miras." Mira is located 350 light-years from Earth in the constellation Cetus, otherwise known as the whale. Coincidentally, Mira and its "whale of a tail" can be found in the tail of the whale constellation. These images were between November 18 and December 15, 2006. |
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Mira Soars Through the Sky
PIA09958
Ultraviolet/Visible Camera
| Title |
Mira Soars Through the Sky |
| Original Caption Released with Image |
New ultraviolet images from NASA's Galaxy Evolution Explorer shows a speeding star that is leaving an enormous trail of "seeds" for new solar systems. The star, named Mira (pronounced my-rah) after the latin word for "wonderful," is shedding material that will be recycled into new stars, planets and possibly even life as it hurls through our galaxy. In figure 1, the upper panel shows Mira's full, comet-like tail as seen only in shorter, or "far" ultraviolet wavelengths, while the lower panel is a combined view showing both far and longer, or "near" ultraviolet wavelengths. The close-up picture at bottom gives a better look at Mira itself, which appears as a pinkish dot, and is moving from left to right in this view. Shed material appears in light blue. The dots in the picture are stars and distant galaxies. The large blue dot on the left side of the upper panel, and the large yellow dot in the lower panel, are both stars that are closer to us than Mira. The Galaxy Evolution Explorer discovered the strange tail during part of its routine survey of the entire sky at ultraviolet wavelengths. When astronomers first saw the picture, they were shocked because Mira has been studied for over 400 years yet nothing like this has ever been documented before. Mira's comet-like tail stretches a startling 13 light-years across the sky. For comparison, the nearest star to our sun, Proxima Centauri, is only about 4 light-years away. Mira's tail also tells a tale of its history -- the material making it up has been slowly blown off over time, with the oldest material at the end of the tail being released about 30,000 years ago (figure 2). Mira is a highly evolved, "red giant" star near the end of its life. Technically, it is called an asymptotic giant branch star. It is red in color and bloated, for example, if a red giant were to replace our sun, it would engulf everything out to the orbit of Mars. Our sun will mature into a red giant in about 5 billion years. Like other red giants, Mira will lose a large fraction of its mass in the form of gas and dust. In fact, Mira ejects the equivalent of the Earth's mass every 10 years. It has released enough material over the past 30,000 years to seed at least 3,000 Earth-sized planets or 9 Jupiter-sized ones. While most stars travel along together around the disk of our Milky Way, Mira is charging through it. Because Mira is not moving with the "pack," it is moving much faster relative to the ambient gas in our section of the Milky Way. It is zipping along at 130 kilometers per second, or 291,000 miles per hour, relative to this gas. Mira's breakneck speed together with its outflow of material are responsible for its unique glowing tail. Images from the Galaxy Evolution Explorer show a large build-up of gas, or bow shock, in front of the star, similar to water piling up in front of a speeding boat. Scientists now know that hot gas in this bow shock mixes with the cooler, hydrogen gas being shed from Mira,, causing it to heat up as it swirls back into a turbulent wake. As the hydrogen gas loses energy, it fluoresces with ultraviolet light, which the Galaxy Evolution Explorer can detect. Mira, also known as Mira A, is not alone in its travels through space. It has a distant companion star called Mira B that is thought to be the burnt-out, dead core of a star, called a white dwarf. Mira A and B circle around each other slowly, making one orbit about every 500 years. Astronomers believe that Mira B has no effect on Mira's tail. Mira is also what's called a pulsating variable star. It dims and brightens by a factor of 1,500 every 332 days, and will become bright enough to see with the naked eye in mid-November 2007. Because it was the first variable star with a regular period ever discovered, other stars of this type are often referred to as "Miras." Mira is located 350 light-years from Earth in the constellation Cetus, otherwise known as the whale. Coincidentally, Mira and its "whale of a tail" can be found in the tail of the whale constellation. These images were between November 18 and December 15, 2006. |
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Explosions - Large and Small
PIA09221
| Title |
Explosions - Large and Small |
| Original Caption Released with Image |
"" Click on the image for full resolution animation (""Half Resolution) This animation shows an artist's concept of Z Camelopardalis (Z Cam), a stellar system featuring a collapsed, dead star, or white dwarf, and a companion star. The white dwarf, the bright white object within the disk on the left, sucks matter from its more sedate companion star, on the right. The stolen material forms a rotating disk of gas and dust around the white dwarf. After a certain amount of material accumulates, the star erupts in a huge nova explosion, known as a "classical nova." After that explosion, the star continues to flare up with smaller bursts, which is why Z Cam is known today as a recurrent dwarf Nova. The remnants of the classical nova explosion form a ghostly shell, which provides lingering evidence of the violent outburst. The animation ends with an image taken by NASA's Galaxy Evolution Explorer on Jan. 25, 2004, when the star system was undergoing a period of relative calm. Astronomers divide exploding binary star systems into two classes -- recurrent dwarf novae, which erupt in smaller, "hiccup-like" blasts, and classical novae, which undergo huge explosions. A link between the two types of novae had been predicted, but the observations from the Galaxy Evolution Explorer bolster the theory that some binary systems undergo both types of explosions. |
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Explosions - Large and Small
PIA09221
| Title |
Explosions - Large and Small |
| Original Caption Released with Image |
"" Click on the image for full resolution animation (""Half Resolution) This animation shows an artist's concept of Z Camelopardalis (Z Cam), a stellar system featuring a collapsed, dead star, or white dwarf, and a companion star. The white dwarf, the bright white object within the disk on the left, sucks matter from its more sedate companion star, on the right. The stolen material forms a rotating disk of gas and dust around the white dwarf. After a certain amount of material accumulates, the star erupts in a huge nova explosion, known as a "classical nova." After that explosion, the star continues to flare up with smaller bursts, which is why Z Cam is known today as a recurrent dwarf Nova. The remnants of the classical nova explosion form a ghostly shell, which provides lingering evidence of the violent outburst. The animation ends with an image taken by NASA's Galaxy Evolution Explorer on Jan. 25, 2004, when the star system was undergoing a period of relative calm. Astronomers divide exploding binary star systems into two classes -- recurrent dwarf novae, which erupt in smaller, "hiccup-like" blasts, and classical novae, which undergo huge explosions. A link between the two types of novae had been predicted, but the observations from the Galaxy Evolution Explorer bolster the theory that some binary systems undergo both types of explosions. |
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Older Galaxy Pair Has Surpri
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PIA09106
Infrared Array Camera (IRAC)
| Title |
Older Galaxy Pair Has Surprisingly Youthful Glow |
| Original Caption Released with Image |
Poster Version A pair of interacting galaxies might be experiencing the galactic equivalent of a mid-life crisis. For some reason, the pair, called Arp 82, didn't make their stars early on as is typical of most galaxies. Instead, they got a second wind later in life -- about 2 billion years ago -- and started pumping out waves of new stars as if they were young again. Arp 82 is an interacting pair of galaxies with a strong bridge and a long tail. NGC 2535 is the big galaxy and NGC 2536 is its smaller companion. The disk of the main galaxy looks like an eye, with a bright "pupil" in the center and oval-shaped "eyelids." Dramatic "beads on a string" features are visible as chains of evenly spaced star-formation complexes along the eyelids. These are presumably the result of large-scale gaseous shocks from a grazing encounter. The colors of this galaxy indicate that the observed stars are young to intermediate in age, around 2 million to 2 billion years old, much less than the age of the universe (13.7 billion years). The puzzle is: why didn't Arp 82 form many stars earlier, like most galaxies of that mass range? Scientifically, it is an oddball and provides a relatively nearby lab for studying the age of intermediate-mass galaxies. This picture is a composite captured by Spitzer's infrared array camera with light at wavelength 8 microns shown in red, NASA's Galaxy Evolution Explorer combined 1530 and 2310 Angstroms shown in blue, and the Southeastern Association for Research in Astronomy Observatory light at 6940 Angstroms shown in green. |
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Older Galaxy Pair Has Surpri
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PIA09106
Infrared Array Camera (IRAC)
| Title |
Older Galaxy Pair Has Surprisingly Youthful Glow |
| Original Caption Released with Image |
Poster Version A pair of interacting galaxies might be experiencing the galactic equivalent of a mid-life crisis. For some reason, the pair, called Arp 82, didn't make their stars early on as is typical of most galaxies. Instead, they got a second wind later in life -- about 2 billion years ago -- and started pumping out waves of new stars as if they were young again. Arp 82 is an interacting pair of galaxies with a strong bridge and a long tail. NGC 2535 is the big galaxy and NGC 2536 is its smaller companion. The disk of the main galaxy looks like an eye, with a bright "pupil" in the center and oval-shaped "eyelids." Dramatic "beads on a string" features are visible as chains of evenly spaced star-formation complexes along the eyelids. These are presumably the result of large-scale gaseous shocks from a grazing encounter. The colors of this galaxy indicate that the observed stars are young to intermediate in age, around 2 million to 2 billion years old, much less than the age of the universe (13.7 billion years). The puzzle is: why didn't Arp 82 form many stars earlier, like most galaxies of that mass range? Scientifically, it is an oddball and provides a relatively nearby lab for studying the age of intermediate-mass galaxies. This picture is a composite captured by Spitzer's infrared array camera with light at wavelength 8 microns shown in red, NASA's Galaxy Evolution Explorer combined 1530 and 2310 Angstroms shown in blue, and the Southeastern Association for Research in Astronomy Observatory light at 6940 Angstroms shown in green. |
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Large Face on Spiral Galaxy
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PIA07904
GALEX Telescope
| Title |
Large Face on Spiral Galaxy NGC 3344 |
| Original Caption Released with Image |
Ultraviolet image of the large face on spiral galaxy NGC 3344. The inner spiral arms are wrapped so tightly that they are difficult to distinguish. |
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Face on Barred and Ringed Sp
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PIA07909
GALEX Telescope
| Title |
Face on Barred and Ringed Spiral Galaxy NGC 3351 |
| Original Caption Released with Image |
Ultraviolet image (left) and visual image (right) of the face on barred and ringed spiral galaxy NGC 3351 (M95). The morphological appearance of a galaxy can change dramatically between visual and ultraviolet wavelengths. In the case of M95, the nucleus and bar dominate the visual image. In the ultraviolet, the bar is not even visible and the ring and spiral arms dominate. |
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Barred Spiral Galaxy NGC 136
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PIA07901
GALEX Telescope
| Title |
Barred Spiral Galaxy NGC 1365 |
| Original Caption Released with Image |
Ultraviolet image of the barred spiral galaxy NGC 1365, which is a member of the Fornax Cluster of Galaxies. |
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A Barred Spiral Galaxy, and
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PIA07900
GALEX Telescope
| Title |
A Barred Spiral Galaxy, and the Small Elliptical Companion Galaxy NGC 1097A |
| Original Caption Released with Image |
Ultraviolet image of the interacting pair NGC 1097, a barred spiral galaxy, and the small elliptical companion galaxy NGC 1097A. |
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