Image: Shredded disk
David A. Aguilar
In this artist's conception, a protoplanetary disk of gas and dust, shown in red, is being shredded by the powerful gravitational tides of our galaxy's central black hole.
updated 9/11/2012 11:04:52 PM ET 2012-09-12T03:04:52

Astronomers have found a cloud of gas and dust around a young star being devoured by the giant black hole at the heart of our Milky Way galaxy — a find that suggests planets can form in galactic cores.

The supermassive black hole thought to lurk at the center of the Milky Way is named Sagittarius A*. Scientists estimate it is about 4.3 million times the mass of the sun.

For the most part, very little light is seen emerging from near Sagittarius A*, aside from radio waves and some modest X-ray or infrared flares, suggesting that not much matter is currently getting fed into it. This absence of data limits what investigators can deduce about the black hole's properties and behavior, as well as those of the other supermassive black holes believed to be at the centers of all large galaxies.

Recently, astronomers gazing at Sagittarius A* through the Very Large Telescope in Chile spotted a dusty gas cloud three times the mass of Earth hurtling toward the center of the galaxy at more than 5.2 million mph (8.4 million kilometers per hour).

The cloud is putting out five times as much light as the sun as it zips along. The cloud should achieve its closest approach to the black hole in June 2013, reaching a distance of 270 times that of Earth from the sun. [ Milky Way Black Hole Eats Space Cloud in 2013 (Video)]

Scientists are monitoring this mysterious cloud's behavior as it moves closer toward the black hole's accretion zone — the region where matter begins its death spiral into the black hole. A new theoretical model now suggests the cloud is probably the shredded remains of a protoplanetary disk surrounding a young, low-mass star — the kind of structures from which worlds eventually develop.

The star apparently came from the inner edge of a ring of stars 4 million to 8 million years old, circling Sagittarius A* at a distance of about one-tenth of a light-year. Interactions within this ring could have flung this star, which by itself is too small for astronomers to see directly, toward the black hole on an elliptical, oval-shaped orbit.

The center of the Milky Way might ordinarily seem like an inhospitable place to try to form a planet, since the young, massive, super-hot stars that often dwell there typically explode as supernovas, blasting out shock waves and bathing the region with intense radiation.

"The galactic center is one of the most extreme environments in the galaxy," said lead study author Ruth Murray-Clay, a theoretical astrophysicist at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass.

Nevertheless, the existence of protoplanetary disks near the center of the galaxy suggests that worlds can form in this cosmic maelstrom, as well as comets and asteroids.

"If our explanation for the gas cloud we see is shown to be true, that means protoplanetary disks — and by extension, planets — can be found everywhere," Murray-Clay told

  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

"It's fascinating to think about planets forming so close to a black hole," study author Abraham Loeb, a theoretical astrophysicist at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., told "If our civilization inhabited such a planet, we could have tested Einstein's theory of gravity much better, and we could have harvested clean energy from throwing our waste into the black hole."

Future research might look for evidence of planets, comets and asteroids falling into supermassive black holes in other galaxies, such as the bright flares dying worlds would release as they get ripped apart. The glowing remains of protoplanetary disks getting sucked into black holes could shed light on low-mass stars near galactic cores that are otherwise too faint to be detected.

As the star continues its plunge over the next year, more and more of the disk's outer material will get torn away. The stripped gas will swirl into the maw of the black hole, and friction will heat it to incandescence, causing it to glow in X-rays.

"We're really looking forward to next summer," Loeb said.

Murray-Clay and Loeb detailed their findings online on Tuesday in the journal Nature Communications.

You can follow on Twitter @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