Scientists pinpoint gamma rays emission from 'nova' explosion

The heart of an exploding star was recently studied by the International team or astronomers that pinpointed the locations where a stellar explosion called a 'nova', emitted gamma rays (extremely high energy radiation).

The study was done by combining data from telescopes that are hundreds or even thousands of kilometers apart.

Highly-detailed images produced using radio telescopes from across Europe and America have revealed how the gamma-ray emissions are produced, something which mystified astronomers when they were first observed in 2012.

Tim O'Brien of The University of Manchester's Jodrell Bank Observatory, one of the international team of astronomers who worked on the study, explained, "When it exploded it brightens hugely, leading in some cases to the appearance of a new star in the sky, hence the term nova and in June of 2012, NASA's Fermi spacecraft detected gamma rays coming from a nova called V959 Mon, some 6500 light-years from Earth.

This observation, along with studies made with the e-MERLIN telescope array in the UK, and further VLA observations in 2014, provided the scientists with information that allowed them to put together a picture of how the radio knots, and the gamma rays, were produced.

In the first stage the white dwarf and its companion give 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 blows off a faster wind of particles moving mostly outward along the poles of the orbital plane. When the faster-moving polar flow hits the slower-moving material, the shock accelerates particles to the speeds needed to produce the gamma rays, and the knots of radio emission.

The research was published in the journal Nature.