• 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.

  • Team aims to score cosmic goal

    Gemini Observatory / AURA

    The Gemini Observatory's image of Kronberger 61 shows the shell of ionized gas surrounding a dying star.

    By Alan Boyle, Science Editor, NBC News

    Professional and amateur astronomers are teaming up to study a cosmic "soccer ball" with a tricky goal in mind: understanding how the death throes of a star are affected by the company it keeps.

    The focus of this game is Kronberger 61, a planetary nebula discovered several months ago by Austrian amateur astronomer (and professional physicist) Matthias Kronberger. He belongs to a group called the "Deep Sky Hunters," which combs through imagery from the Digital Sky Survey and other sources looking for celestial objects worthy of further study. The hunters have found about 100 faint planetary nebulae, shells of glowing ionized gas that are thrown off by sunlike stars in the waning years of their lives.

    Kronberger 61 is worth noting for aesthetic reasons alone: The image above, captured by the Gemini North telescope in Hawaii, highlights the nebula's emissions from twice-ionized oxygen. The dying star can be seen as a point of bluish light close to the center of the ball-shaped nebula.

    But this soccer ball, also known as Kn 61, is also notable because of its location. It happens to be within the Kepler planet-hunting probe's field of view, an 105-square-degree area that takes up about as much of the sky as your hand held at arm's length. There's a chance that Kepler could determine whether there are planets or faint companion stars circling Kn 61's main star.

    "Kn 61 is among a rather small collection of planetary nebulae that are strategically placed within Kepler's gaze," Orsola De Marco of Australia's Macquarie University said in the Gemini Observatory's news release about the find. "Explaining the puffs left behind when medium-sized stars like our sun expel their last breaths is a source of heated debate among astronomers, especially the part that companions might play. It literally keeps us up at night!"

    The Kepler science team has now added Kn 61 to its target list of more than 150,000 stars, and within months, astronomers might be able to determine whether the star has companions, said George Jacoby of the Giant Magellan Telescope Organization and the Carnegie Observatories (Pasadena). "This was not an object that was known by Kepler to be valuable early on," Jacoby told me.

    Jacoby serves as principal investigator for the program to get follow-up observations of Kn 61 with Kepler, and also acts as the liaison with the Deep Sky Hunters.

    "Without this close collaboration with amateurs, this discovery would probably not have been made before the end of the Kepler mission," Jacoby said in today's news release. "Professionals, using precious telescope time, aren't as flexible as amateurs who did this using existing data and in their spare time. This was a fantastic pro-am collaboration of discovery."

    The Deep Sky Hunters have identified yet another planetary nebula in the Kepler field, and possibly a third prospect. Jacoby said astronomers would be playing an "odds game," hoping that one of the nebulae will reveal something interesting about the effects of companion objects on a dying star's gaseous shell. If the gamble pays off, the scientific payoff could be significant.

    De Marco said that planetary nebula present a "profound mystery."

    "Some recent theories suggest that planetary nebulae form only in close binary or even planetary systems — on the other hand, the conventional textbook explanation is that most stars, even solo stars like our sun, will meet this fate," she said. "That might just be too simple."

    Will this pro-am team hit the goal, or will luck be against them? The project has already produced a beautiful image of a ghostly planetary nebula, and it's sparked some intriguing scientific questions. So the way I see it, they've already scored.

    Update for 3 p.m. ET: Jacoby sent along further information about Kronberger 61: The star is located in the constellation Lyra, very close to the western edge of Cygnus. Determining its distance "is a very difficult question, because these kinds of objects (planetary nebulae) have been very resistant to having their distances measured accurately." Jacoby's rough estimate is 13,000 light-years, "but it could be half that or twice that." He says Kronberger discovered the nebula in January, using data from the Digital Sky Survey.

    "The star is very likely to have a mass about 60 percent that of the sun," Jacoby wrote in his email. "The age of the star is much harder to estimate, but it is likely between 2 billion and 8 billion years old. The nebula around the star was probably blown off about 15,000 to 30,000 years ago (after accounting for the time delay due to the distance of 13,000 light years, or 28,000 to 43,000 years ago if you include that light travel time)."

    More about planetary nebulae:

    The discovery and the new Gemini images were presented today at "Planetary Nebulae: An Eye to the Future," an International Astronomical Union symposium in Puerto de la Cruz in the Canary Islands.

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

  • NASA / ESA / Hubble

    The planetary nebula NGC 6210 lies 6,500 light-years from Earth in the constellation Hercules.

    The inside story of a dying star

    The curious nebula NGC 6210 has been compared to a "turtle in space," based on the shape of its colorful clouds of glowing gas. This image, released Monday by the European Space Agency's Hubble Space Telescope team, looks inside the turtle to chart the nebula's inner region in unprecedented detail. You can see a delicate bluish bubble of gas, enclosing an amorphous, reddish gas formation with pillars and filaments sticking out. Up toward the top, there's a red blurp that's part of a jet of material stretching out from the scene. (In the earlier Hubble view, that blurp represents one of the turtle's appendages.)

    NGC 6210, discovered in 1825 by the German astronomer Friedrich Georg Wilhelm Struve, is a fine example of a planetary nebula. The nebulae were called "planetary" because they looked like planetary disks through the small telescopes used in the olden days. But they actually represent the death throes of a sunlike star nearing the end of its life. When the star's fusion fuel runs out, it becomes unstable and starts throwing off its outer layers of gas. You can make out the remnant of the star as a bright spot in the middle of the colorful clouds. Astronomers say our own sun will meet a similar fate, in 5 billion years or so.

    More about planetary nebulae:

    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.