A mysterious star in the Milky Way has been revealed to have a pancake-shaped disc of gas surrounding it which is 1,000 times the diameter of our solar system.

Astronomers have spent decades trying to find out more about the star - called Nasty 1 - which is far bigger than our sun.

It has been identified as a Wolf-Rayet star, which loses its hydrogen-filled outer layers quickly to expose its super-hot and bright helium core.

But while astronomers using NASA's Hubble Space Telescope expected to see two lobes of gas coming out of the star, they were surprised to see a huge disc surrounding it.

The area of gas is around 1,000 times the diameter of our solar system and may have formed as a result of a clash with a nearby star. It could be evidence of a rare space event.

NASA said: "The vast disk is nearly two trillion miles wide, and may have formed from an unseen companion star that snacked on the outer envelope of the newly formed Wolf-Rayet."

Study leader Jon Mauerhan said: "We were excited to see this disc-like structure because it may be evidence for a Wolf-Rayet star forming from a binary interaction.

"There are very few examples in the galaxy of this process in action because this phase is short-lived, perhaps lasting only 100,000 years, while the timescale over which a resulting disc is visible could be only 10,000 years or less."

The name of the star comes from its space catalogue name of NaSt1.