Renegade stars speed through interstellar space
Like out-of-control teens running riot through their neighborhoods, a new class of renegade stars has been found tearing through interstellar space at up to 112,000 mph, five times the speed of a normal star.
NASA’s Hubble Space Telescope found these stellar runaways by focusing on the wakes they leave in interstellar gas, just like the wakes left in water by a speeding boat.
According to research presented this week at an American Astronomical Society meeting in Long Beach, the wakes of these misfits extend for billions, even trillions of miles, equivalent to the distance from the Earth to Neptune.
Finding the stars was a surprise because astronomers weren’t looking for the stellar mischief-makers, said Raghvendra Sahai of NASA’s Jet Propulsion Laboratory, who led the team of researchers.
“When I first saw the images I said, ‘Wow. This is like a bullet speeding through the interstellar medium,’ ” he said.
Sahai and his team found 14 rampaging stars. All are within our Milky Way galaxy and are within a few thousand light-years of Earth.
Much about the stars remains mysterious, however, such as where they were born. They are believed to be medium-size stars, from about three times to 10 times the mass of the sun, according to Mark Morris, a UCLA astronomer who was part of the research team.
They are also believed to be young. A leading theory for their behavior is that each was kicked out of its birthplace, most likely by the interaction with other stars.
One likely explanation, according to Sahai, is that one of a pair of companion stars explodes in a supernova, the force of which sends its partner star spinning into space.
Or two stars could collide with a third star with enough force to eject it from its birthplace.
The lightest of the three would be the loser, Sahai said.
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