Violent gas collisions that produced supersonic shock fronts in a dying star are seen in a detailed image from NASA's Hubble Space Telescope.

The densest parts of the nebula are composed of material ejected recently by the central star and accelerated in opposite directions.

A team of Spanish and US astronomers used NASA's Hubble Space Telescope to study how the gas stream rams into the surrounding material, shown in blue.

Astronomers were able to distinguish the warmest parts of the gas heated by the violent shocks and found that they form a complex double-bubble shape.

The bright yellow-orange colors in the picture show how dense, high-speed gas is flowing from the star, like supersonic speeding bullets ripping through a medium in opposite directions.