Top Ten Space Pictures of 2007

Top Ten Space Photos of 2007
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2. Bizarre Object Found Circling Star
(originally posted September 14, 2007)

An object detected orbiting a neutron star is among the strangest planet-mass bodies ever found, astronomers said in September.

Instead of circling around a normal star, the low-mass objectlikely the "skeleton" of a smaller starorbits a rapidly spinning pulsar, or neutron star.

The neutron star spins hundreds of times a secondfaster than a kitchen blender.

The odd mass, which was spotted on June 7 by NASA's Swift and Rossi X-ray Timing Explorer (RXTE) satellites, orbits the bigger star in a little less than once an hour.

The body is located about 230,000 miles (370,149 kilometers) away from the starslightly less than the distance from Earth to the moon.

Neutron stars usually slow with age, but the gas spiraling from the bizarre object has likely maintained, or even increased, the star's speed.

The star siphons off gas from the orbiting body, as seen in the above artist's illustration. The gas flow occasionally becomes unstable and causes the bright outbursts that can be seen from Earth.

Astronomers suspect the system was once made up of two stars that formed billions of years ago. Eventually the larger star went supernova, leaving behind the neutron star, while the smaller star expanded into a red giant.

It's unknown whether the smaller star will survive much longer, however.

"It's been taking a beating," Hans Krimm of NASA's Goddard Space Flight Center said in a statement. The neutron star, after all, has been siphoning away its mass for billions of years.

"But that's part of nature."

Christine Dell'Amore

(Top space pictures determined by number of times viewed.)

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—Image courtesy Aurore Simmonet/Sonoma State University
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