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Gamma rays are the most powerful form of radioactive waves known in the universe.

But how these mysterious waves are made, and where exactly they come from have baffled scientists for years.

Now, for the first time, scientists have peered into the heart of an erupting star to uncover the origin of this stunning phenomenon.

Gamma rays, emitted when a star explodes, are the most powerful form of radioactive waves known in the universe. But how these mysterious waves were made and where exactly they come from have baffled scientists for years. Pictured is an artist's impression of gas ejected in the nova explosion

Astronomers, led by Michigan State and Manchester University, made an unexpected discovery when looking at an explosion on the surface of a star.

'We not only found where the gamma rays came from, but also got a look at a previously-unseen scenario that may be common in other nova explosions,' said Laura Chomiuk, of Michigan State University.

A nova occurs in a star that is part of a binary system – two stars orbiting one another.

One star, known as a dense white dwarf, steals matter from the other and the interaction triggers a thermonuclear explosion that flings debris into space.

It was from this explosion from a system known as V959 Mon, located some 5,000 light-years from Earth, that the researchers think the gamma rays were emitted.

It was from an explosion from a system known as V959 Mon, located some 5,000 light years from Earth, that the researchers think the gamma rays were emitted. Artist's impressions of the gas ejected in the nova explosion is pictured

This activity was first detected two years ago by Nasa's Fermi Gamma-ray Space Telescope.

At about that same time, similar activity was being picked up by land-based radio telescopes around the world, revealing two distinct knots of radio emission.

These knots were then seen to move away from each other.

Scientists believe the white dwarf and its companion gave up some of their orbital energy to boost some of the explosion material, making the ejected material move outward faster in the plane of their orbit.

Later, the white dwarf blew off a faster wind of particles moving mostly outward along the poles of the orbital plane.

When the faster-moving polar flow hit the slower-moving material, the shock accelerated particles to the speeds needed to produce the gamma rays, and the knots of radio emission.

This artist's impression is believed to be the exact replica of the moment a star explodes. When the faster-moving polar flow hits the slower-moving material, the shock accelerated particles to the speeds needed to produce the gamma rays, and the knots of radio emission

'By watching this system over time, and seeing how the pattern of radio emission changed, then tracing the movements of the knots, we saw the exact behaviour expected from this scenario,' Professor Chomiuk said.

Since that initial detection by Fermi, the spacecraft has detected gamma rays from three additional nova explosions in other star systems.

'This mechanism may be common to such systems,' said Professor Chomiuk. 'The reason the gamma rays were first seen in V959 Mon is because it's closer to us.'

Because the type of ejection detected in V959 Mon also is seen in other binary star systems, the new insights might help astronomers understand how those systems develop.

'We may be able to use novae as a 'testbed' for improving our understanding of this critical stage of binary evolution,' Professor Chomiuk said.

Gamma rays can be dangerous and are capable of killing living cells. The medical field uses gamma rays, along with X-rays and other forms of high-energy radiation, to treat cancer.

Fortunately, by the time gamma rays travel across the universe to us, they are absorbed by the Earth's atmosphere.