Astronomers have discovered an unbound star travelling at a whopping 1,200 kilometres per second – the fastest ever speed recorded for such an object in the Milky Way. Researchers say that the star will eventually leave the Milky Way as it’s not bound by gravity.

Astronomers believe that US708 was once a 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.

Astronomers at Queen’s University Belfast say that the discovery of the unbound star will help shed light on the mysterious double-star systems that give rise to thermonuclear explosions or “type Ia” supernovae. Such type of explosions have long been used to calculate the distances to faraway galaxies – a measurement which helps to determine how the universe is changing and expanding.

“It is very exciting to have contributed to this important discovery. It brings us a step closer to solving the type Ia puzzle,” said Rubina Kotak from the astrophysics centre at the Queen’s University.

Kotak and Ken Smith 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 was able to determine the full 3D motion of the star and measure how quickly it is moving across the plane of the sky.

European Southern Observatory fellow, Stephan Geier, who led the study, said: “Several types of stars have been suspected of causing the explosion of a white dwarf as supernova of type Ia. Until now, none of them could be confirmed. Now we have found a delinquent on the run bearing traces from the crime scene.”