Astronomers' hopes raised by glimpse of possible new planet

Bright speck in space near Alpha Centauri A may be evidence of asteroids or dust - or a technical glitch

Astronomers have glimpsed what may be a previously unknown planet circling one of the closest stars to Earth.

Researchers spotted the bright dot near Alpha Centauri A, one of a pair of stars that swing around each other so tightly they appear as one in the southern constellation of Centaurus. The stars form what is called a binary system 4.37 light years away, a mere stone's throw in cosmic terms.