ESO / H. Boffin
This ESO Very Large Telescope image shows the planetary nebula Fleming 1 in the constellation of Centaurus (The Centaur). New observations suggest that a rare pair of white dwarf stars lies at the heart of this object, with their orbital motions explaining the nebula's remarkably symmetric jet structures.
updated 11/8/2012 3:58:27 PM ET 2012-11-08T20:58:27

A pair of stars orbiting one another inside a planetary nebula appear to be the cosmic powerhouse behind the oddball nebula's spectacular jets, scientists say.  

The discovery stands to settle a long-running debate over the shape of jets streaming from the planetary nebula Fleming 1. Those jets, which appear oddly knotted and curved, are powered by the orbital interactions of the binary stars, the new study found. Their gas is shared between the bigger star and its much smaller companion.

"This is a big project to understand strange, asymmetric shapes of planetary nebulas," said study leader Henri Boffin, a Chile-based astronomer with the European Southern Observatory. According to scientists, 80 percent of planetary nebulas have lopsided shapes.

ESO / L. Calcada
An artist's view of how the spectacular jets of planetary nebulas like Fleming 1 are sculpted by the interactions of binary stars.

Despite their name, planetary nebulas have nothing to do with planets. They are the swan song of dying white dwarf stars that are close to the size of Earth's sun — between one and eight times its mass, Boffin told [ Photos: Amazing Nebulas in Deep Space ]

Finessing Fleming 1 observations

Boffin's team used the Very Large Telescope in northern Chile to look at Fleming 1 in the southern constellation Centaurus. The planetary nebula is named after Williamina Fleming, a maid-turned-astronomer for the Harvard College Observatory, who discovered the nebula in 1910.

For decades astronomers wondered about the strange shapes of gas surrounding the nebula. Boffin and his colleagues combined new observations with computer models to confirm that binary white dwarf stars were at work.

Most binary stars orbit each other every few hundred or few thousand years, but a look at Fleming 1's spectrum revealed its stars are a lot faster than that. Rapidly changing lines in the spectrum showed the stars whip around each other every 1.2 days.

"It's a very close binary system," Boffin said, adding that other systems already discovered have similar orbital periods.

The stars in Fleming 1 once shared a common envelope of gas that surrounded the system. This is common in some kinds of binary star systems, Boffin said. However, that envelope is not there now.

The research is detailed in the Friday edition of the journal Science.

Faucet of gas jets
Originally, the two stars in Fleming were far apart. The bigger star evolved late in life from a red giant to a humongous "asymptotic giant branch" star. At this point it had the combined width of several hundreds of solar disks.

Gas streaming off this massive star then flowed toward the much smaller star nearby, a cooling white dwarf. It was at this point that jets of gas, like water from a faucet, "turned on" and began streaming out material away from the stars.

Boffin said this period was just a snapshot in time in the lifetime of a star, lasting only 5,000 to 10,000 years.

Ejecting the envelope
Over time, the giant star lost all its gas and became a white dwarf. The gas enveloped both of the stars, pushing them closer together.

  1. Space news from
    1. KARE
      Teen's space mission fueled by social media

      Science editor Alan Boyle's blog: "Astronaut Abby" is at the controls of a social-media machine that is launching the 15-year-old from Minnesota to Kazakhstan this month for the liftoff of the International Space Station's next crew.

    2. Buzz Aldrin's vision for journey to Mars
    3. Giant black hole may be cooking up meals
    4. Watch a 'ring of fire' solar eclipse online

As the stars drew closer, the envelope of gas was ejected and the jet "faucets" turned off.

Boffin's team suggested the process at Fleming 1 is common among binary star systems in planetary nebulas, but he added that more observations will be needed to firm up the theory.

"This is the first time we've seen these jets fresh out of the oven," Boffin said.

"One of them is still shredding the envelope, which is why we can only infer (its creation) by numerical simulations and the theory of the formation. ... There are still many things that are not clear."

Follow Elizabeth Howell @howellspace, or @Spacedotcom. We're also on Facebook and Google+.

© 2013 All rights reserved. More from

Photos: Month in Space: January 2014

loading photos...
  1. Southern stargazing

    Stars, galaxies and nebulas dot the skies over the European Southern Observatory's La Silla Paranal Observatory in Chile, in a picture released on Jan. 7. This image also shows three of the four movable units that feed light into the Very Large Telescope Interferometer, the world's most advanced optical instrument. Combining to form one larger telescope, they are greater than the sum of their parts: They reveal details that would otherwise be visible only through a telescope as large as the distance between them. (Y. Beletsky / ESO) Back to slideshow navigation
  2. A balloon's view

    Cameras captured the Grandville High School RoboDawgs' balloon floating through Earth's upper atmosphere during its ascent on Dec. 28, 2013. The Grandville RoboDawgs’ first winter balloon launch reached an estimated altitude of 130,000 feet, or about 25 miles, according to coaches Mike Evele and Doug Hepfer. It skyrocketed past the team’s previous 100,000-feet record set in June. The RoboDawgs started with just one robotics team in 1998, but they've grown to support more than 30 teams at public schools in Grandville, Mich. (Kyle Moroney / AP) Back to slideshow navigation
  3. Spacemen at work

    Russian cosmonauts Oleg Kotov, right, and Sergey Ryazanskiy perform maintenance on the International Space Station on Jan. 27. During the six-hour, eight-minute spacewalk, Kotov and Ryazanskiy completed the installation of a pair of high-fidelity cameras that experienced connectivity issues during a Dec. 27 spacewalk. The cosmonauts also retrieved scientific gear outside the station's Russian segment. (NASA) Back to slideshow navigation
  4. Special delivery

    The International Space Station's Canadian-built robotic arm moves toward Orbital Sciences Corp.'s Cygnus autonomous cargo craft as it approaches the station for a Jan. 12 delivery. The mountains below are the southwestern Alps. (NASA) Back to slideshow navigation
  5. Accidental art

    A piece of art? A time-lapse photo? A flickering light show? At first glance, this image looks nothing like the images we're used to seeing from the Hubble Space Telescope. But it's a genuine Hubble frame that was released on Jan. 27. Hubble's team suspects that the telescope's Fine Guidance System locked onto a bad guide star, potentially a double star or binary. This caused an error in the tracking system, resulting in a remarkable picture of brightly colored stellar streaks. The prominent red streaks are from stars in the globular cluster NGC 288. (NASA / ESA) Back to slideshow navigation
  6. Supersonic test flight

    A camera looking back over Virgin Galactic's SpaceShipTwo's fuselage shows the rocket burn with a Mojave Desert vista in the background during a test flight of the rocket plane on Jan. 10. Cameras were mounted on the exterior of SpaceShipTwo as well as its carrier airplane, WhiteKnightTwo, to monitor the rocket engine's performance. The test was aimed at setting the stage for honest-to-goodness flights into outer space later this year, and eventual commercial space tours.

    More about SpaceShipTwo on PhotoBlog (Virgin Galactic) Back to slideshow navigation
  7. Red lagoon

    The VLT Survey Telescope at the European Southern Observatory's Paranal Observatory in Chile captured this richly detailed new image of the Lagoon Nebula, released on Jan. 22. This giant cloud of gas and dust is creating intensely bright young stars, and is home to young stellar clusters. This image is a tiny part of just one of 11 public surveys of the sky now in progress using ESO telescopes. (ESO/VPHAS team) Back to slideshow navigation
  8. Fire on the mountain

    This image provided by NASA shows a satellite view of smoke from the Colby Fire, taken by the Multi-angle Imaging SpectroRadiometer aboard NASA's Terra spacecraft as it passed over Southern California on Jan. 16. The fire burned more than 1,863 acres and forced the evacuation of 3,700 people. (NASA via AP) Back to slideshow navigation
  9. Where stars are born

    An image captured by NASA's Spitzer Space Telescope shows the Orion Nebula, an immense stellar nursery some 1,500 light-years away. This false-color infrared view, released on Jan. 15, spans about 40 light-years across the region. The brightest portion of the nebula is centered on Orion's young, massive, hot stars, known as the Trapezium Cluster. But Spitzer also can detect stars still in the process of formation, seen here in red hues. (NASA / JPL-Caltech) Back to slideshow navigation
  10. Cygnus takes flight

    Orbital Sciences Corp.'s Antares rocket rises from NASA's Wallops Flight Facility on Wallops Island, Va, on Jan. 9. The rocket sent Orbital's Cygnus cargo capsule on its first official resupply mission to the International Space Station. (Chris Perry / NASA) Back to slideshow navigation
  11. A long, long time ago...

    This long-exposure picture from the Hubble Space Telescope, released Jan. 8, is the deepest image ever made of any cluster of galaxies. The cluster known as Abell 2744 appears in the foreground. It contains several hundred galaxies as they looked 3.5 billion years ago. Abell 2744 acts as a gravitational lens to warp space, brightening and magnifying images of nearly 3,000 distant background galaxies. The more distant galaxies appear as they did more than 12 billion years ago, not long after the Big Bang. (NASA / NASA via AFP - Getty Images) Back to slideshow navigation
  12. Frosty halo

    Sun dogs are bright spots that appear in the sky around the sun when light is refracted through ice crystals in the atmosphere. These sun dogs appeared on Jan. 5 amid brutally cold temperatures along Highway 83, north of Bismarck, N.D. The temperature was about 22 degrees below zero Fahrenheit, with a 50-below-zero wind chill.

    Slideshow: The Year in Space (Brian Peterson / The Bismarck Tribune via AP) Back to slideshow navigation
  1. Editor's note:
    This image contains graphic content that some viewers may find disturbing.

    Click to view the image, or use the buttons above to navigate away.

  2. Editor's note:
    This image contains graphic content that some viewers may find disturbing.

    Click to view the image, or use the buttons above to navigate away.

  3. Editor's note:
    This image contains graphic content that some viewers may find disturbing.

    Click to view the image, or use the buttons above to navigate away.

  4. Editor's note:
    This image contains graphic content that some viewers may find disturbing.

    Click to view the image, or use the buttons above to navigate away.


Discussion comments


Most active discussions

  1. votes comments
  2. votes comments
  3. votes comments
  4. votes comments