Nasa captures image of exploding supernova five billion times brighter than the sun

Supernova was seen in a galaxy 70 million light-years away, burning at a heat of over 100,000 Kelvin

An exploding supernova in a galaxy 70 million light-years away has been recorded by the Hubble Space Telescope.

The rare event outshone the entire host galaxy, coming from a white dwarf star that gathered material from its companion star.

A white dwarf is a degenerating star that is reaching the end of its life cycle. When it has depleted its nuclear fuel, the star expels its outer material, reaching temperatures exceeding 100,000 Kelvin.

When the white dwarf reaches a critical mass, its core becomes hot enough to start a nuclear fusion reaction, turning it into a planet-sized atomic bomb.

The force of this reaction tears the star apart, and in this instance the energy unleashed was the equivalent of the radiance of five billion suns, Nasa says.

This particular supernova, classified as SN 2018gv, was spotted in the spiral galaxy NGC 2525 in mid-January 2018 by amateur astronomer Koichi Itagaki.

By February, it was being recorded by the Hubble telescope to help scientists track the expansion rate of the universe.

In the time-lapse, scientists could see the supernova appearing as a brightly shining star near the edge of the galaxy. It quickly becomes the brightest object in the galaxy, before fading from sight.

“No Earthly fireworks display can compete with this supernova, captured in its fading glory by the Hubble Space Telescope," said Adam Riess of the Space Telescope Science Institute (STScI) and Johns Hopkins University in a statement.

Supernovae of this kind all peak at the same brightness, and as such are known as "standard candles."

This is because they act as “cosmic tape measures," Nasa says. With information about the brightness of the supernova as constant, astronomers can calculate the distances of their host galaxies. 

This allows the scientists to measure the expansion rate of the universe. 

In May, the Hubble Space Telescope reached its 30th birthday. Its first photo was of the binary star HD96755 from its wide field camera, captured in black and white.

In August, the telescope captured its first observation of a total lunar eclipse - the first time that a total lunar eclipse has been captured from a space telescope, and also the first time one has been studied in ultraviolet wavelengths.

Scientists hope they can use this data to examine exoplanets, giving us a better understanding in the search for alien life and interstellar travel.