NASA News Conference On Newly Found Extreme Objects

 

Flaring Black Hole

 

This artist’s concept illustrates what the flaring black hole called GX 339-4 might look like. Infrared observations from NASA’s Wide-field Infrared Survey Explorer (WISE) reveal the best information yet on the chaotic and extreme environments of this black hole’s jets. 

 

GX 339-4 likely formed from a star that exploded. It is surrounded by an accretion disk (red) of material being pulled onto the black hole from a neighboring star (yellow orb). Some of this material is shot away in the form of jets (yellow flows above and below the disk). The region close in to the black hole glows brightly in infrared light.

Image credit: NASA

 

Jabbah and Associates

 

No, it’s not a gang of intergalactic mobsters from the famous Star Wars movies. Jabbah is the name of the bright star right of center, surrounded by a red colored dust cloud. The Arabic name means “the forehead of the scorpion.” This view from NASA’s Wide-field Infrared Survey Explorer, or WISE, takes in an area of the sky in the constellation of Scorpius surrounding Jabbah, which is larger than a grid of eight by eight full moons. 

 

Though Jabbah appears to be a single star, it is actually a whole system of stars (possibly as many as seven), each of which is many times more massive, larger, hotter and more luminous than the sun. The Jabbah system is located about 440 light-years away from us and lights up a giant cloud of dust and gas near it. The cloud near Jabbah is designated IC 4592, and the portion farthest away to the far left in the image is IC 4601. 

 

The other bright stars in this image are mostly part of the “Upper Scorpius Association” and were probably once all born in the same cluster about 5 million years ago. These stars are all moving apart as the cluster ages, and are probably no longer bound to each other by gravity. 

 

Another star of interest in the image is 9 Scorpii, located in the lower right corner with the bright red dust cloud primarily on one side of it. 9 Scorpii is another very massive star that is probably a member of the Upper Scorpius Association. It is also moving through space at an enormous speed of 1,000 kilometers per second (224,000 miles per hour). With such a speed, the star may be a runaway star once in a system with a more massive member that exploded as a supernova and sent 9 Scorpii zooming through space. The red cloud near it may be a bow shock in front of it similar to the stars called Alpha Cam and Zeta Oph. 

 

This image was made from observations by all four infrared detectors aboard WISE. Blue and cyan (blue-green) represent infrared light at wavelengths of 3.4 and 4.6 microns, which is primarily from stars, the hottest objects pictured. Green and red represent light at 12 and 22 microns, which is primarily from warm dust. 

 

Image credit: NASA/JPL-Caltech/UCLA

 

A Trio of Brown Dwarfs

 

This artist’s conception illustrates what brown dwarfs of different types might look like to a hypothetical interstellar traveler who has flown a spaceship to each one. Brown dwarfs are like stars, but they aren’t massive enough to fuse atoms steadily and shine with starlight — as our sun does so well.

 

On the left is an L dwarf, in the middle is a T dwarf, and on the right is a Y dwarf. The objects are progressively cooler in atmospheric temperatures as you move from left to right. Y dwarfs are the newest and coldest class of brown dwarfs and were discovered by NASA’s Wide-field Infrared Survey Explorer, or WISE. WISE was able to detect these Y dwarfs for the first time because it surveyed the entire sky deeply at the infrared wavelengths at which these bodies emit most of their light. 

 

The L dwarf is seen as a dim red orb to the eye. The T dwarf is even fainter and appears with a darker reddish, or magenta, hue. The Y dwarf is dimmer still. Because astronomers have not yet detected Y dwarfs at the visible wavelengths we see with our eyes, the choice of a purple hue is done mainly for artistic reasons. The Y dwarf is also illustrated as reflecting a faint amount of visible starlight from interstellar space. 

 

In this rendering, the traveler’s spaceship is the same distance from each object. This illustrates an unusual property of brown dwarfs — that they all have the same dimensions, roughly the size of the planet Jupiter, regardless of their mass. This mass disparity can be as large as fifteen times or more when comparing an L to a Y dwarf, despite the fact that both objects have the same radius.

 

The three brown dwarfs also have very different atmospheric temperatures. A typical L dwarf has a temperature of 2,600 degrees Fahrenheit (1,400 degrees Celsius). A typical T dwarf has a temperature of 1,700 degrees Fahrenheit (900 degrees Celsius). The coldest Y dwarf so far identified by WISE has a temperature of less than about 80 degrees Fahrenheit (25 degrees Celsius). 

Image credit: NASA/JPL-Caltech

 

Reigning Title-Holder for Coldest Brown Dwarf

 

NASA’s Wide-field Infrared Survey Explorer, or WISE, has uncovered the coldest brown dwarf known so far (green dot in very center of this infrared image). Called WISE 1828+2650, this chilly star-like body isn’t even as warm as a human body, at less than about 80 degrees Fahrenheit (25 degrees Celsius). Like other brown dwarfs, it began life like a star, collapsing under its own weight into a dense ball of gas. But, unlike a star, it didn’t have enough mass to fuse atoms at its core, and shine steadily with starlight. Instead, it has continued to cool and fade since its birth, and now gives off only a feeble amount of infrared light. WISE’s highly sensitive infrared detectors were able to catch the glow of this object during its all-sky scan, which lasted from Jan. 2010 to Feb. 2011. 

 

WISE 1828+2650 is located in the constellation Lyra. The blue dots are a mix of stars and galaxies. 

 

This view shows three of WISE’s four infrared channels, color-coded blue, green and red, with blue showing the shortest infrared wavelengths and red, the longest. 

Image credit: NASA/JPL-Caltech/UCLA

 

 

‘Y Dwarf’ Chillin’ in Space

 

This artist’s conception illustrates what a “Y dwarf” might look like. Y dwarfs are the coldest star-like bodies known, with temperatures that can be even cooler than the human body. NASA’s Wide-field Infrared Survey Explorer uncovered these elusive objects for the first time, using its heat-sensing, infrared vision. The telescope found six Y dwarfs, ranging in atmospheric temperatures from 350 degrees Fahrenheit (175 degrees Celsius) to less than about 80 degrees Fahrenheit (25 degrees Celsius). 

 

Y dwarfs belong to a larger family of objects called brown dwarfs. Brown dwarfs begin their lives like stars but they never accumulate enough mass to fuse atoms steadily at their cores and shine with starlight — as our sun does so well. Instead, they fade and cool with time, giving off most of their light in infrared wavelengths. 

 

WISE was able to pick up this faint glow for six Y dwarfs, which are the coldest class of brown dwarfs and the latest letter in the stellar classification scheme. This scheme describes stars of all temperatures, beginning with the hottest “O” stars and now ending with the coldest Y dwarfs. The entire scheme includes the classes: O, B, A, F, G, K, M, L, T, Y. Our yellow sun belongs to the G class of stars. M stars are colder than our sun, and reddish in color. 

While the O through K classes are all considered stars, M and L objects are a mixture of stars and brown dwarfs, and T and Y objects are all brown dwarfs. The term “brown dwarfs” was chosen because at that time, astronomers didn’t know what colors these objects would actually have at the visible wavelengths our eyes see, and brown is not a true color of light (there are no “brown photons”). Astronomers now know that T dwarfs would appear reddish, or magenta, to the eye. But they are not certain what color Y dwarfs are, since these objects have not been detected at visible wavelengths. The purple color shown here was chosen mainly for artistic reasons. In addition, the Y dwarf is illustrated as reflecting a faint amount of visible starlight from interstellar space.

Image credit: NASA/JPL-Caltech

Searching for the Origins of the Dinosaur-Killing Asteroid

Scientists think that a giant asteroid, which broke up long ago in the main asteroid belt between Mars and Jupiter, eventually made its way to Earth and led to the extinction of the dinosaurs. Data from NASA’s WISE mission likely rules out the leading suspect, a member of a family of asteroids called Baptistina, so the search for the origins of the dinosaur-killing asteroid goes on.

This artist’s concept shows a broken-up asteroid.

Image credit: NASA/JPL-Caltech

WISE Catches a Runaway Star in Flames

NASA’s Wide-field Infrared Survey Explorer, or WISE, captured this view of a runaway star racing away from its original home. Seen here surrounded by a glowing cloud of gas and dust, the star AE Aurigae appears to be on fire. Appropriately, the cloud is called the Flaming Star nebula.

A runaway star is one that is hurled into high-speed motion through a supernova explosion or encounter with nearby stars. Like an angry teenager who storms out of the house after a family fight, runaway stars are ejected from their birthplace and race off to other parts of the galaxy.

The runaway star AE Aurigae was likely born in the Trapezium cluster, which is located in the constellation Orion. It formed as a binary-star system with the star Mu Columbae. Approximately 2.5 million years ago, these two stars are thought to have collided with another binary-star system in the Trapezium Cluster. This collision sent both AE Aurigae and Mu Columbae hurtling through space in opposite directions at a speed of 100 kilometers per second (over 200,000 miles per hour). Today, AE Aurigae can be seen in the constellation Auriga hundreds of light-years to the north of its home, while its former companion Mu Columbae is located hundreds of light-years to the south in the constellation Columba.

The wind from AE Aurigae blows away electrons from the gas surrounding it. This ionized gas begins to emit light, creating what is known as an emission nebula. The star also heats up nearby dust, causing it to glow in infrared wavelengths. As seen in visible light, this dust reflects the light of nearby stars, so it is called a reflection nebula.

The colors seen in this image represent specific wavelengths of infrared light. Hot stars scattered throughout the image show up as blue and cyan. Blue represents light emitted at wavelengths of 3.4 microns, while cyan represents 4.6 microns. The gas of the emission nebula appears green, representing 12-micron wavelengths. The dust of the reflection nebula appears primarily red, representing 22-micron light.

One interesting aspect of this image is that the edges of the reflection nebula appear lavender. This is because at its edges the nebula is both emitting light at longer, 22-micron wavelengths, and scattering shorter, 3.4-micron light. Since WISE represents 22-micron light as red and 3.4-micron light as blue, the combination of the two appears in this image as lavender.

Image credit: NASA/JPL-Caltech/UCLA

 

A Super Special Galaxy

There’s something special going on in the nearby Circinus galaxy, as revealed by this image from NASA’s Wide-field Infrared Survey Explorer, or WISE. The Circinus galaxy is located in the constellation of Circinus and is obscured by the plane of our Milky Way galaxy. At a distance of 14 million light-years, it is one of the nearest galaxies, yet is largely unexplored because the Milky Way veils it. 

 

There are so many stars and so much dust from our own galaxy obscuring the Circinu galaxy. In fact, this galaxy has two extended spiral arms, which look like a great green “S” in this WISE image. These arms had not been seen until NASA’s Spitzer Space Telescope and WISE observed them. The infrared wavelengths of light detected by these observatories pierce through the foreground dust of the Milky Way, revealing aspects of the special nature of the Circinus galaxy. 

At the center of the “S,” the core of the Circinus galaxy glows intensely in longer wavelengths of light (colored red in this WISE image). Circinus is what astronomers call an “active” galaxy, meaning a large fraction of its luminosity is coming from the core of the galaxy. All that luminous energy is believed to come from two sources. The first is probably a ring of star formation surrounding the core. Some recent gravitational disturbance induced the material around the core to begin collapsing and forming stars at an accelerated rate. 

 

Star formation makes a lot of dust, which is then heated and glows in infrared light. The other source is an active galactic nucleus, which is a supermassive black hole surrounded by a disk of matter that is slowly falling into the hole. That disk of matter contains a great deal of gas and dust. The material nearest the black hole is so hot that it produces intense X-ray and ultraviolet light. Dust further out in the disk absorbs much of that light, heating the dust and making it also glow in the infrared. Circinus contains the closest active galaxy nucleus to us. 

This image was made from observations by all four infrared detectors aboard WISE. Blue and cyan (blue-green) represent infrared light at wavelengths of 3.4 and 4.6 microns, which is primarily light from stars. Green and red represent light at 12 and 22 microns, which is primarily light emitted from warm dust.

Image Credit: NASA/JPL-Caltech/UCLA

Zeta Ophiuchi — Runaway Star Plowing Through Space Dust

The blue star near the center of this image is Zeta Ophiuchi. When seen in visible light it appears as a relatively dim red star surrounded by other dim stars and no dust. However, in this infrared image taken with NASA’s Wide-field Infrared Survey Explorer, or WISE, a completely different view emerges. Zeta Ophiuchi is actually a very massive, hot, bright blue star plowing its way through a large cloud of interstellar dust and gas.

Astronomers theorize that this stellar juggernaut was likely once part of a binary star system with an even more massive partner. It’s believed that when the partner exploded as a supernova, blasting away most of its mass, Zeta Ophiuchi was suddenly freed from its partner’s pull and shot away like a bullet moving 24 kilometers per second (54,000 miles per hour). Zeta Ophiuchi is about 20 times more massive and 65,000 times more luminous than the sun. If it weren’t surrounded by so much dust, it would be one of the brightest stars in the sky and appear blue to the eye. Like all stars with this kind of extreme mass and power, it subscribes to the ‘live fast, die young’ motto. It’s already about halfway through its very short 8-million-year lifespan. In comparison, the sun is roughly halfway through its 10-billion-year lifespan. While the sun will eventually become a quiet white dwarf, Zeta Ophiuchi, like its ex-partner, will ultimately die in a massive explosion called a supernova.

Perhaps the most interesting features in this image are related to the interstellar gas and dust that surrounds Zeta Ophiuchi. Off to the sides of the image and in the background are relatively calm clouds of dust, appearing green and wispy, slightly reminiscent of the northern lights. Near Zeta Ophiuchi, these clouds look quite different. The cloud in all directions around the star is brighter and redder, because the extreme amounts of ultraviolet radiation emitted by the star are heating the cloud, causing it to glow more brightly in the infrared than usual.

Even more striking, however, is the bright yellow curved feature directly above Zeta Ophiuchi. This is a magnificent example of a bow shock. In this image, the runaway star is flying from the lower right towards the upper left. As it does so, its very powerful stellar wind is pushing the gas and dust out of its way (the stellar wind extends far beyond the visible portion of the star, creating an invisible ‘bubble’ all around it). And directly in front of the star’s path the wind is compressing the gas together so much that it is glowing extremely brightly (in the infrared), creating a bow shock. It is akin to the effect you might see when a boat pushes a wave in front it as it moves through the water. This feature is completely hidden in visible light. Infrared images like this one from WISE shed an entirely new light on the region.

The colors used in this image represent specific wavelengths of infrared light. Blue and cyan (blue-green) represent light emitted at wavelengths of 3.4 and 4.6 microns, which is predominantly from stars. Green and red represent light from 12 and 22 microns, respectively, which is mostly emitted by dust. 

Image credit: NASA/JPL-Caltech/UCLA

Supergiant Star Near Giraffe’s Hind Foot

 

NASA’s Wide-field Infrared Survey Explorer, or WISE, captured this colorful image of the nebula BFS 29 surrounding the star CE-Camelopardalis, found hovering in the band of the night sky comprising the Milky Way. Most of the gas and dust in this image cannot be seen directly in visible light, but WISE’s detectors revealed exquisite new details, and even some hidden stars.

 

The nebulous interstellar gas and dust in this image is known as BFS 29. “BFS” stands for Blitz, Fich, and Stark — the three astronomers who identified and catalogued 65 new star-forming regions in 1982 (the “29″ simply means that it’s the 29th object in their catalog). In visible light, BFS 29 can be seen, but only very slightly. This is because the dust scatters and reflects some of the light from nearby stars, hence its classification as a reflection nebula. The gas in BFS 29 also contains large amounts of ionized hydrogen — referred to by astronomers as “H II.” Hence, the nebula is also classified as an HII region. Reflection nebulae and HII regions are often associated with star formation.