Australian scientists have spotted a star moving at unbelievable speeds – so fast it generates a glowing blue "bow shock" as it races on its journey.

It is moving nearly 2000 kilometres per second, making it the fastest star in our galaxy.

That's despite it being twice the size of our sun, and weighing about 4 octillion tonnes – a four followed by 27 zeroes.

The only thing scientists know of that would be capable of accelerating a star to that speed is the supermassive black hole lurking in the centre of our galaxy.