Astronomers have found the largest star yet detected - up to 20 million times brighter than the Sun - using the Very Large Telescope in Chile.

Named R136a1, the star is thought to have started off with a mass of up to 320 times that of the Sun and the new discovery has doubled the previously accepted limit of solar mass.

The research, conducted by scientists from Britain, Malaysia and Germany, was published in scientific journal The Monthly Notices of the Royal Astronomical Society.

R136a1 was discovered as part of a series of massive stars found in two young star clusters in the star-dense heart of the Tarantula Nebula in the Large Magellanic Cloud, by a team of astronomers led by Professor Paul Crowther of Sheffield University in northern England.

The researchers discovered it using the Very Large Telescope, located in the Atacama Desert in northern Chile, and operated by the European Southern Observatory (ESO).

It features four eight-metre diameter telescopes and is described by the ESO as "the world's biggest eye on the sky". They also used data from the NASA/European Space Agency's Hubble Space Telescope.

This close-up of the R136 cluster, taken with the Very Large Telescope at the infrared wavelength of 2.2 microns, reveals a clutch of supermassive stars that includes R136a1. The field of view is about 5 arcseconds wide.
Although the star has since shed some of its weight, it is so powerful that if it replaced the Sun as the centre of our solar system, it would make life on Earth impossible because of the strength of its ultraviolet radiation.