• Helix remix reveals 'Eye of God' nebula in a new light

    NASA / JPL-Caltech / SSC

    Layers of gas and dust show up clearly in this color-coded composite picture of the Helix Nebula. Ultraviolet wavelengths, as seen by the GALEX probe, are shown in blue. Infrared wavelengths, as seen by NASA's Spitzer Space Telescope, are presented in red, yellow and green. The nebula appears magenta in the center, where the two sets of data overlap. A portion of the extended field beyond the nebula is from NASA's Wide-field Infrared Survey Explorer.

    By Alan Boyle, Science Editor, NBC News


    More than 600 light-years away, the Helix Nebula stares at us like the Eye of God — or like the Eye of Sauron in the "Lord of the Rings" film saga. This new picture combines readings from two space telescopes to fill out our picture of the eye.

    The pinkish light you see pouring from the center of the image doesn't show up in visible-light images — but in this view, it's an essential part of the staring-eye effect. That comes from a combination of the infrared emissions spotted by NASA's Spitzer Space Telescope; and ultraviolet emissions that were detected by the Galaxy Evolution Explorer, or GALEX, which was launched by NASA and is now being lent to Caltech for continuing research.

    Here's the story behind the eye: The Helix, also known as NGC 7293, was created when a dying sunlike star started blasting away its outer layers of gas and dust. Radiation has cleared away the area around the star, which is now a dense white dwarf, but the colorful gaseous shells of gas that were thrown off continue to spread outward. GALEX traces the ultraviolet glow of those shells in shades of deep blue. Meanwhile, Spitzer sees the infrared emissions from the nebula's gas and dust. The different infrared wavelengths are shown in red, yellow and green.

    You can compare the ultraviolet-plus-infrared view with this infrared view from Spitzer, or with this one from the European Southern Observatory's VISTA telescope, or with this video that takes you on a 3-D tour through the Hubble Space Telescope's visible-light image. (As a bonus, you get a lesson about the Helix Nebula and other planetary nebulae along with the pretty pictures.)

    Scientists believe the blast that caused the Helix Nebula is the same fate that awaits our own sun in 5 billion years or so. We won't have to worry about that for a while, but the "Eye of God" serves as a reminder that even stars sometimes go out with a blaze of glory.

    More blazes of glory:

    Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

  • This view of the Orion Nebula, incorporating infrared observations from NASA's Spitzer Space Telescope and the European Space Agency's Herschel telescope, highlights fledgling stars hidden in gas and clouds.

    Orion Nebula reveals an infrared rainbow

    By Alan Boyle, Science Editor, NBC News

    The sparkles of hidden stars are revealed in a picture of the Orion Nebula that shows off the colors of the infrared rainbow.

    Do you see those twinkling lights, strung along a line that starts at the top right corner of the image? Those are stars in the earliest stages of their evolution, swathed in clouds of gas and dust. Astronomers focused on those protostars with the infrared-sensitive cameras of NASA's Spitzer Space Telescope and the European Space Agency's Herschel space telescope.

    This color-coded image shows the scene as observed by Spitzer in one set of infrared wavelengths (8.0 and 24 microns, shown here in shades of blue), and by Herschel in somewhat longer wavelengths (70 and 160 microns, shown in green and red, respectively). Herschel monitored the emissions from cold dust particles once a week for six weeks, while Spitzer kept track of the emissions from the warmer dust, filling out the infrared rainbow.

    Astronomers found that the stars' brightness in infrared wavelengths varied by more than 20 percent during the observational time frame. That's surprising, because the astronomers expected variations in brightness to play out over a time frame measured in years or even centuries rather than weeks.

    What could cause the short-term twinkling? The astronomers theorized that lumpy filaments of gas might be streaming inward from a star's outer environs, temporarily warming up the dusty disk of material surrounding the star. An alternative hypothesis would be that material occasionally piles up on the inner edge of the disk, casting 'shadows" that temporarily darken the outer disk. In any case, the observations from Herschel and Spitzer show that the birth process for baby stars is a rough-and-tumble affair, with significant ups and downs.

    Members of the Herschel science team, led by Nicolas Billot, an astronomer at the Institut de Radioastronomie Millimetrique in Grenada, Spain, are preparing a paper about their findings.

    "Herschel's exquisite sensitivity opens up new possibilities for astronomers to study star formation, and we are very excited to have witnessed short-term variability in Orion protostars," Billot said today in a photo advisory. "Follow-up observations with Herschel will help us identify the physical processes responsible for the variability."

    More infrared wonders:

    Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding Cosmic Log's Google+ page to your circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.

  • Astronomers share galactic glories

    NASA / JPL-Caltech / CfA

    A bubbling cauldron of starbirth is highlighted in this new image of the Cygnus X star-forming region from NASA's Spitzer Space Telescope. The colors indicate different wavelengths of infrared light, ranging from the blue of stars to the red and green of interstellar dust. The stars have blown bubbles, or cavities, in the dust and gas — a violent process that triggers both the death and birth of stars. The brightest, yellow-white regions are warm centers of star formation. Cygnus X is about 4,500 light-years away in the constellation Cygnus, or the Swan.

    By Alan Boyle, Science Editor, NBC News



    It's a great day for the world's great observatories: Astronomers around the world have saved up some of their most groundbreaking images to share during this week's meeting of the American Astronomical Society in Austin, Texas.

    The Chandra X-Ray Observatory and the European Southern Observatory have teamed up to present their view of "El Gordo," a big, fat galaxy cluster weighed down with the mass of 2 quadrillion suns. Meanwhile, the Hubble Space Telescope's science team is showing off pictures of the most distant developing galaxy cluster ever detected, 13.1 billion light-years away.

    Here are a few pictures from some of the world's other top space observatories: NASA's Spitzer Space Telescope, which focused on a star-forming region in our Milky Way galaxy known as Cygnus X; NASA's Wide-field Infrared Survey Explorer, which scanned a broad section of the Milky Way; and portraits of the Large and Small Magellanic Clouds, two of the Milky Way's satellite galaxies, courtesy of Spitzer and the European Space Agency's Herschel Space Telescope.

    Stay tuned for more wonders from the AAS meeting as the week wears on — and if you haven't seen it yet, be sure to spread your browser wide and click through our Year in Space Pictures Slideshow.

    NASA / JPL-Caltech / UCLA

    This enormous section of the Milky Way galaxy is a mosaic of images from NASA's Wide-field Infrared Survey Explorer, or WISE. The different colors represent specific wavelengths of infrared light: The blue points of light are stars, while green and red represent light mostly emitted by interstellar dust. The constellations Cassiopeia and Cepheus are featured in this 1,000-square degree expanse.

    ESA / NASA / JPL-Caltech / STScI

    This image shows the Large Magellanic Cloud galaxy in infrared light as seen by the European Space Agency's Herschel Space Observatory and NASA's Spitzer Space Telescope. In the instruments' combined data, this nearby dwarf galaxy looks like a fiery, circular explosion. Rather than fire, however, those ribbons are actually giant ripples of dust spanning tens or hundreds of light-years. Significant fields of star formation are noticeable in the center, just left of center and at right. The brightest center-left region is called 30 Doradus, or the Tarantula Nebula, for its appearance in visible light.

    ESA / NASA / JPL-Caltech / STScI

    This image shows the Small Magellanic Cloud galaxy in infrared light from the European Space Agency's Herschel Space Observatory and NASA's Spitzer Space Telescope. The Large and Small Magellanic Clouds are the two biggest satellite galaxies of our home galaxy, the Milky Way. In this composite view, the irregular distribution of dust in the Small Magellanic Cloud becomes clear. A stream of dust extends to the left in this image, known as the galaxy's "wing," and a bar of star formation appears on the right. The colors indicate different temperatures in the dust that permeates the Cloud.


    Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.

  • Starry continent shines brighter

    L. Rebull / Caltech / JPL / NASA

    Four views of the North American Nebula show how different wavelengths provide different perspectives on astronomical objects. The visible-light view at upper left highlights the nebula's similarity to the continent. The red region to the right is known as the "Pelican Nebula" due to its birdlike appearance. The upper-right view includes both visible and infrared observations. In the two lower views, only the infrared readings from Spitzer are displayed. Click on the image to download larger versions.

    By Alan Boyle, Science Editor, NBC News

    North America has been thoroughly explored, but the North America Nebula is a different matter entirely. Fresh infrared images of the continent-shaped star-forming region, lying in the constellation Cygnus, reveal thousands of stars that can't be seen in visible light. The new pictures come from NASA's Spitzer Space Telescope, whose infrared-sensitive cameras are designed to cut through interstellar dust and spot the glittering prizes within.

    Previously, only about 200 stars could be seen — but the new observations, accepted for publication in the Astrophysical Journal Supplement Series, add more than 2,000 candidate stars to the list.

    You can see how the North America Nebula (or is that the North American Nebula?) got its name by looking at the visible-light view in the upper-left quadrant of the image above. The relatively bright area toward the left is reminiscent of the eastern United States and Mexico. The dark, central knots of cosmic dust stand in for the Atlantic and the Gulf of Mexico. There's a reddish swirl of dust on the right side of the picture that is known as the Pelican Nebula, again because of its shape. Can you see the pelican's long beak?

    All these features seem to disappear in the Spitzer views at lower left and right, because the space telescope's cameras can cut through the dark areas of the "Gulf of Mexico" dust cloud. Different colors stand for different wavelengths of infrared light detected by Spitzer's infrared array camera and multiband imaging photometer. This "Hidden Universe" video guides you through the imagery:

    "One of the things that makes me so excited about this image is how different it is from the visible image, and how much more we can see in the infrared than in the visible," the study's lead author, Luisa Rebull of NASA's Spitzer Science Center at the California Institute of Technology, said today in an image advisory. "The Spitzer image reveals a wealth of detail about the dust and the young stars here."

    There are a few mysteries left to solve. For example, astronomers aren't sure exactly how far away the nebula is, for example. Further observations from Spitzer could refine the current estimate of 1,800 light-years. Another puzzler has to do with the nebula's power source. There should be some massive stars that dominate the nebula and drive the formation of later generations of stars, but not even Spitzer was able to find them. The clues so far suggest that the bright stars are still hidden behind the central "Gulf of Mexico" clouds.

    More examples of infrared imagery:

    Connect with the Cosmic Log community by "liking" the log's Facebook page or following @b0yle on Twitter. You can also check out "The Case for Pluto," Alan's book about the controversial dwarf planet and the search for new worlds.