Renegade rampaging stars found

Los Angeles: Like out-of-control teens running through their neighbourhoods, a new class of renegade stars has been found tearing through interstellar space at up to 179,200 km/h, five times the speed of a normal star.

Nasa's Hubble Space Telescope found these stellar runaways by focusing on the wakes they make in interstellar gas, just like the wakes left behind in water by a speeding boat.

According to research presented this week at American Astronomical Society meeting in Long Beach on the west side of Los Angeles, the wakes of these misfits extend for billions, even trillions of miles, equivalent to the distance from the Earth to Neptune.

Location

Finding the stars was a surprise because astronomers were not looking for them, 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.

The rampaging stars found by Sahai and his team currently number 14. All are within our Milky Way galaxy.

Much about the stars remains mysterious, however, such as where they were born. They are believed to be medium-sized stars, according to Mark Morris, a University of California, Los Angeles, astronomer who was part of the research team.

They also are believed to be young. A leading theory for their behaviour is that each was kicked out of its birth-home, most likely by the interaction with other stars.