Phantoms In The Dust

Variable star V838 Monocerotis lies near the edge of our Milky Way Galaxy, about 20,000 light-years from our sun. Still, ever since a sudden outburst was detected in January 2002, this enigmatic star has taken the center of an astronomical stage. As astronomers watch, light from the outburst echoes across pre-existing dust shells around V838 Mon, progressively illuminating ever more distant regions.
This stunning image of swirls of dust surrounding the star was recorded by the Hubble Space Telescope in September 2006. The picture spans about 14 light-years. Astronomers expect the expanding echoes to continue to light up the dusty environs of V838 Mon for at least the rest of the current decade. Researchers have now found that V838 Mon is likely a young binary star, but the cause of its extraordinary outburst remains a mystery.
Image credit: NASA, ESA, and H. Bond (STScI)

Cosmic Eye in the Helix Nebula

Dust makes this cosmic eye look red. This eerie Spitzer Space Telescope image shows infrared radiation from the well-studied Helix Nebula (NGC 7293), which is a mere 700 light-years away in the constellation Aquarius. The two light-year diameter shroud of dust and gas around a central white dwarf has long been considered an excellent example of a planetary nebula, representing the final stages in the evolution of a sun-like star.
Spitzer data show the nebula's central star is itself immersed in a surprisingly bright infrared glow. Models suggest the glow is produced by a dust debris disk. Even though the nebular material was ejected from the star many thousands of years ago, the close-in dust could be generated by collisions in a reservoir of objects analogous to our own solar system's Kuiper Belt or cometary Oort cloud. Formed in the distant planetary system, the comet-like bodies have otherwise survived even the dramatic late stages of the star's evolution.
Image credit: NASA, JPL-Caltech, Kate Su (Steward Obs, U. Arizona) et al.

Bubble of stars

RCW 79 is seen in the southern Milky Way, 17,200 light-years from Earth in the constellation Centaurus. The bubble is 70-light years in diameter, and probably took about one million years to form from the radiation and winds of hot young stars.
The balloon of gas and dust is an example of stimulated star formation. Such stars are born when the hot bubble expands into the interstellar gas and dust around it. RCW 79 has spawned at least two groups of new stars along the edge of the large bubble. Some are visible inside the small bubble in the lower left corner. Another group of baby stars appears near the opening at the top.
NASA's Spitzer Space Telescope easily detects infrared light from the dust particles in RCW 79. The young stars within RCW79 radiate ultraviolet light that excites molecules of dust within the bubble. This causes the dust grains to emit infrared light that is detected by Spitzer and seen here as the extended red features.
Image credit: NASA/JPL-Caltech/E. Churchwell (Univ. of Wisconsin, Madison)

Tapestry in Orion

This glowing region reveals arcs and bubbles formed when stellar winds - streams of charged particles ejected by the Trapezium stars - collide with material in the Orion Nebula.
This crisp image is part of a tapestry of star formation that varies from jets fired by stars still embedded in their dust and gas cocoons to disks of material encircling young stars that could be the building blocks of future solar systems, taken from a mosaic containing a billion pixels by Hubble's Advanced Camera for Surveys. The resulting image uncovered thousands of stars never seen before in visible light. Some are merely one-hundredth the brightness of previously viewed Orion stars.
Among the stars Hubble spotted for the first time in visible light in Orion were young brown dwarfs and a small population of possible binary brown dwarfs (two brown dwarfs orbiting each other). Brown dwarfs are so-called "failed stars." These cool objects are too small to be ordinary stars, because they cannot sustain nuclear fusion in their cores the way our sun does. Comparing the characteristics of newborn stars and brown dwarfs in their natal environment provides unique information about how they form.
Image credit: NASA, ESA, M. Robberto (Space Telescope Science Institute/ESA) and the Hubble Space Telescope Orion Treasury Project Team

Bubble Nebula

This Hubble Space Telescope image reveals an expanding shell of glowing gas surrounding a hot, massive star in our Milky Way Galaxy, the shell of which is being shaped by strong stellar winds of material and radiation produced by the bright star at the left, which is 10 to 20 times more massive than our sun.
These fierce winds are sculpting the surrounding material -- composed of gas and dust -- into the curved shape that astronomers have dubbed it the Bubble Nebula (NGC 7635). The nebula is 10 light-years across, more than twice the distance from Earth to the nearest star. Only part of the bubble is visible in this image. The glowing gas in the lower right-hand corner is a dense region of material that is getting blasted by radiation from the nebula's massive star. The radiation is eating into the gas, creating finger-like features. This interaction also heats up the gas, causing it to glow.
Image credit: NASA

Orion's Babies

This image from NASA's Spitzer Space Telescope shows infant stars "hatching" in the head of the hunter constellation, Orion. Astronomers suspect that shockwaves from a supernova explosion in Orion's head nearly three million years ago may have initiated this newfound birth.
The region featured in this Spitzer image is called Barnard 30, located approximately 1,300 light-years away and sits on the right side of Orion's "head," just north of the massive star Lambda Orionis.
Wisps of green in the cloud are organic molecules called polycyclic aromatic hydrocarbons. These molecules are formed any time carbon-based materials are burned incompletely. On Earth, they can be found in the sooty exhaust from automobile and airplane engines. They also coat the grills where charcoal-broiled meats are cooked.
Tints of orange-red in the cloud are dust particles warmed by the newly forming stars. The reddish-pink dots at the top of the cloud are very young stars embedded in a cocoon of cosmic gas and dust. Blue spots throughout the image are background Milky Way along this line of sight.
Image credit: NASA/JPL-Caltech/ Laboratorio de Astrofísica Espacial y Física Fundamental

Baby Stars

Infant stars glow gloriously in this infrared image of the Serpens Constellation's star-forming region, located approximately 8484 light-years away.
Glowing pink baby stars are embedded in the cosmic cloud of gas and dust that collapsed to create them. Dusty disks of cosmic debris that may eventually form planets surround the stars in this image taken by the Spitzer Space Telescope.
Image credit: NASA/JPL/University of Arizona

Pistol Nebula

The Pistol Nebula, one of the intrinsically brightest stars in our galaxy, appears as the bright white dot in the center of this image taken with NASA's Hubble Space Telescope. Hubble's Near Infrared Camera and Multi-Object Spectrometer (NICMOS) was needed to take the picture, because the star is hidden at the galactic center, behind obscuring dust. NICMOS' infrared vision penetrated the dust to reveal the star, which is glowing with the radiance of 10 million suns.
The image also shows one of the most massive stellar eruptions ever seen in space. The radiant star has enough raw power to blow off two expanding shells (magenta) of gas equal to the mass of several of our suns. The largest shell is so big (4 light-years) it would stretch nearly all the way from our sun to the next nearest star. The outbursts seen by Hubble are estimated to be only 4,000 and 6,000 years old, respectively.
Despite such a tremendous mass loss, astronomers estimate the extraordinary star presently may be 100 times more massive than our Sun, and may have started with as much as 200 solar masses of material, but it is violently shedding much of its mass.
The star is 25,000 light-years away in the direction of the constellation Sagittarius. Despite its great distance, the star would be visible to the naked eye as a modest 4th magnitude object if it were not for the dust between it and the Earth.
This false-color image is a composite of two separately filtered images taken with the NICMOS on Sept. 13, 1997. The field of view is 4.8 light-years across.
Image credit: NASA and Don F. Figer (UCLA)

IC349 and Merope

In the famous Pleiades star cluster, a star's light slowly destroys a passing cloud of gas and dust. The star, Merope, lies just off the upper right edge of this image taken by the Hubble Space Telescope.
The cloud, known as IC 349, and the star have been in existence for millions of years. In the past 100,000 years, however, part of the cloud has by chance moved so close to the star - only 3,500 times the Earth-Sun distance - that the star's light affects the cloud's dust in an unusual manner.
Pressure of the star's light significantly repels the dust in the reflection nebula with smaller dust particles being repelled more strongly. Eventually parts of the dust cloud have become stratified and point toward Merope, with the closest particles being the most massive and so the least affected by the radiation pressure. A longer term result is the general destruction of the dust by the energetic starlight.
Image credit: NASA/STScI/George H. Herbig and Theodore Simon (IfA, U. Hawaii)

Tarantula Nebula

In the center of star-forming region 30 Doradus lies a huge cluster of the largest, hottest, most massive stars known. These stars, known as the star cluster R136, and part of the surrounding nebula are captured here in this gorgeous visible-light image from the Hubble Space Telescope. Gas and dust clouds in 30 Doradus, also known as the Tarantula Nebula, have been sculpted into elongated shapes by powerful winds and ultraviolet radiation from these hot cluster stars. The 30 Doradus Nebula lies within a neighboring galaxy, the Large Magellanic Cloud, located a mere 170,000 light-years away.
Image credit: NASA, J. Trauger (JPL), J. Westphal (Caltech)

The Snowflake Cluster and the Cone Nebula

Strange shapes and textures can be found in the neighborhood of the Cone Nebula. These patterns result from the tumultuous unrest that accompanies the formation of the open cluster of stars known as NGC 2264, the Snowflake Cluster. To better understand this process, a detailed image of this region was taken in two colors of infrared light by the orbiting Spitzer Space Telescope.
Bright stars from the Snowflake Cluster dot the field. These stars soon heat up and destroy the gas and dust mountains in which they formed. One such dust mountain is the famous Cone Nebula, visible in the above image on the left, pointing toward a bright star near the center of the field. The entire NGC 2264 region is located about 2,500 light years away toward the constellation of the Unicorn (Monoceros).
Image credit: NASA

Star Cluster RCW 38

A mere 6,000 light-years distant and sailing through the constellation Vela, star cluster RCW 38 is full of powerful stars. It's no surprise that these stars, only a million years young with hot outer atmospheres, appear as point-like sources dotting this x-ray image from the orbiting Chandra Observatory.
But the diffuse cloud of x-rays surrounding them is a bit mysterious. The image is colour coded by x-ray energy, with high energies in blue, medium in green and low energy x-rays in red. Just a few light-years across, the cloud, which pervades the cluster, has colours suggesting the x-rays are produced by high energy electrons moving through magnetic fields. Yet a source of energetic electrons, such as shockwaves from exploding stars (supernova remnants) or rotating neutron stars (pulsars), is not apparent in the Chandra data. Whatever their origins, the energetic particles could leave an imprint on planetary systems forming in young star cluster, just as nearby energetic events seem to have affected the chemistry and isotopes found in our own solar system.
Image credit: NASA

Carina Nebula

In celebration of the 17th anniversary of the launch and deployment of NASA's Hubble Space Telescope, this, one of the largest panoramic images ever taken with Hubble's cameras, is being released. It is a 50-light-year-wide view of the central region of the Carina Nebula where a maelstrom of star birth - and death - is taking place.
This image is a mosaic of the nebula assembled from 48 frames taken with Hubble's Advanced Camera for Surveys. The images were taken in the light of neutral hydrogen. Color information was added using data from the Cerro Tololo Inter-American Observatory in Chile. Red corresponds to sulphur, green to hydrogen, and blue to oxygen emission.
The fantasy-like landscape of the nebula is sculpted by the action of outflowing winds and scorching ultraviolet radiation from the monster stars that inhabit this inferno. In the process, these stars are shredding the surrounding material that is the last vestige of the giant cloud from which the stars were born.
The immense nebula contains at least a dozen brilliant stars that are estimated to be 50 to 100 times the mass of our sun. The most unique and opulent inhabitant is the star Eta Carinae, which is in the final stages of its brief and eruptive lifespan, as evidenced by two billowing lobes of gas and dust that presage its upcoming explosion as a titanic supernova.
The fireworks in the Carina region started three million years ago when the nebula's first generation of newborn stars condensed and ignited in the middle of a huge cloud of cold molecular hydrogen. Radiation from these stars carved out an expanding bubble of hot gas. The island-like clumps of dark clouds scattered across the nebula are nodules of dust and gas that are resisting being eaten away by photoionization.

Edge of the Orion Nebula

NASA's Hubble Space Telescope captured this "true color" mosaic of a small portion of the Orion Nebula, taken the Wide Field and Planetary Camera in wide field mode. The image shows a wealth of detail never seen before in the nebula. Newly discovered features include elongated objects oriented on the brightest stars in this region, rapidly expanding plumes of material around young stars and protoplanetary disks.
Image credit: NASA/C.R. O'Dell (Rice University)

Eta Carinae

Eta Car is a massive star, but it's not as bright as it used to be. Now visible only in binoculars or a small telescope, Eta Carinae has a history of spectacular flaring and fading behavior.
In fact, in April of 1843 Eta Car briefly became second only to Sirius as the brightest star in planet Earth's night sky, even though at a distance of about 7,500 light-years, it is about 800 times farther away. Surrounded by a complex and evolving nebula, Eta Carinae is seen near the center of this false-color infrared image, constructed using data from the Midcourse Space Experiment satellite, which mapped the galactic plane in 1996.
In the picture, wispy, convoluted filaments are clouds of dust glowing at infrared wavelengths. Astronomers hypothesize that Eta Car itself will explode as a supernova in the next million years. Massive Eta Car is considered a candidate for a hypernova explosion and the potential source of future gamma-ray bursts.
Image from NASA

Z Camelopardalis

This composite image shows Z Camelopardalis, or Z Cam, a double-star system. The Z Cam system features a collapsed, dead star, called a white dwarf, and its 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 explosion that occurred 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 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.
Image credit: NASA/JPL-Caltech

Red Rectangle

This intriguing image of the intriguing ladder-like structures surrounding a dying star reveals startling new details of one of the most unusual nebulae known in our Milky Way. Cataloged as HD 44179, this nebula is more commonly called the "Red Rectangle" because of its unique shape and color as seen with ground-based telescopes.
This Hubble Space Telescope image reveals a wealth of new features in the Red Rectangle that cannot be seen with ground-based telescopes looking through the Earth's turbulent atmosphere.
Hubble's sharp pictures show that the Red Rectangle is not really rectangular, but has an overall X-shaped structure, which arises from outflows of gas and dust from the star in the center. The outflows are ejected from the star in two opposing directions, producing its peculiar shape. Also remarkable are straight features that appear like rungs on a ladder, making the Red Rectangle look similar to a spider web, a shape unlike that of any other known nebula.
The star in the center of the Red Rectangle is one that began its life as a star similar to our sun. It is now nearing the end of its lifetime, and is in the process of ejecting its outer layers to produce the visible nebula. The shedding of the outer layers began about 14,000 years ago. Eventually, the star will have become smaller and hotter and begin to release a flood of ultraviolet light into the surrounding nebula; at that time, gas in the nebula will begin to fluoresce, producing what astronomers call a planetary nebula.
Image credit: NASA, ESA, Hans Van Winckel (Catholic University of Leuven, Belgium), and Martin Cohen (University of California, Berkeley)

A Red Supergiant's Light Echo

This Hubble Space Telescope image of the star V838 Monocerotis reveals dramatic changes in the illumination of surrounding dusty cloud structures. The effect, called a light echo, unveiled never-before-seen dust patterns when the star suddenly brightened for several weeks in early 2002.
A light echo is light from a stellar explosion echoing off dust surrounding the star that produces enough energy in a brief flash to illuminate surrounding dust. The star presumably ejected the illuminated dust shells in previous outbursts. Light from the latest outburst travels to the dust and then is reflected to Earth.
The phenomena is similar to that of a nova. A typical nova is a normal star that dumps hydrogen onto a compact white-dwarf companion star. The hydrogen piles up until it spontaneously explodes by nuclear fusion -- like a titanic hydrogen bomb -- exposing a searing stellar core with a temperature of hundreds of thousands of degrees Fahrenheit.
By contrast, V838 Monocerotis did not expel its outer layers. Instead, it grew enormously in size. Its surface temperature dropped to temperatures that were not much hotter than a light bulb. This behavior of ballooning to an immense size, but not losing its outer layers, is very unusual and completely unlike an ordinary nova explosion.
The outburst may represent a transitory stage in a star's evolution that is rarely seen. The star has some similarities to highly unstable aging stars called eruptive variables, which suddenly and unpredictably increase in brightness.
V838 Monocerotis is located about 20,000 light-years away from Earth in the direction of the constellation Monoceros, placing the star at the outer edge of our Milky Way galaxy.
Image credit: NASA, ESA, and The Hubble Heritage Team (STScI/AURA)

Solar Plasma Filaments

Hinode, a collaborative mission of the space agencies of Japan, the United States, United Kingdon and Europe, captured these very dynamic pictures of our sun's chromosphere on Jan. 12, 2007. Taken by Hinode's Solar Optical Telescope, this image of the sun reveals the filamentary nature of the plasma connecting regions of different magnetic polarity. The chromosphere is a thin layer of solar atmosphere sandwiched between the visible surface, photosphere and corona.