Fast-Moving Unbound Star Has Broken Galactic Speed Record

The unbound star, named US708, is traveling at 1,200 kilometers per second -- the fastest speed ever recorded for such an object in our galaxy -- meaning it is not held back by gravity and will eventually leave the Milky Way.

US708 is believed to have once been part of a double-star solar system, which also included a massive white dwarf star. The white dwarf is thought to have turned into a 'thermonuclear supernovae' and exploded, kicking US708 and sending it hurtling across space.

The discovery of US708 sheds light on the mysterious double-star systems that give rise to thermonuclear explosions. Thermonuclear, or 'type Ia', supernovae have long been used to calculate the distances to faraway galaxies -- a measurement which helps to determine how the universe is changing and expanding.

A team of scientists from countries across the world made the ground-breaking discovery using data gathered by the Pan-STARRS1 telescope on Mount Haleakala on the Hawaiian island of Maui. Using a range of data gathered over the last 59 years the team were able to determine the full 3-D motion of the star and measure how quickly it is moving across the plane of the sky.

The research was led by Dr. Stephan Geier, European Southern Observatory fellow, and comprised contributions from scientists from a number of countries including Germany, USA, the Netherlands, China and the UK.