Stargazers to see brightest supernova in 25 years

 Amateur stargazers will be able to witness the most visible exploding star since 1954 in skies above Britain this week.

The cosmic event is one of the closest stellar explosions to Earth since 1987, and is the nearest example of its type to be seen from Earth in 40 years.

The exploding star, named PTF-11kly, is predicted to reach its brightest between September 9 and 12 and will visible in clear skies all over Britain.

Supernovae can help scientists measure the size and age of the universe and a team of scientists at Oxford University are tracking the explosion using the Hubble Space Telescope.

Dr Mark Sullivan, the astrophysicist leading the Oxford team examining the supernova said: "This is accessible to anyone with a decent pair of binoculars. For many it could be a once in a lifetime chance to see a supernova blossom and then fade before their eyes. We may not see another like it for over 100 years."

It will appear blueish-white just above and to the left of the last two stars in the Plough in the Ursa Major constellation.

Observers are advised to stay away from street lights for maximum visibility.

The supernova was first spotted by astronomers in California.

The discovery was made in what was believed to be the first hours of the rare cosmic explosion using a special telescope at the Palomar Observatory near San Diego and powerful supercomputers at a government laboratory in Berkeley, US.

The detection so early of a supernova so near has created a worldwide stir among astronomers, who are clamouring to observe it with every telescope at their disposal, including the giant Hubble Space Telescope.

Scientists behind the discovery at the Lawrence Berkeley National Laboratory and the University of California at Berkeley say the extraordinary phenomenon – labelled by the rather obscure designation PTF 11kly – will likely become the most-studied supernova in history.

"It is an instant cosmic classic," said Peter Nugent, the senior scientist at UC Berkeley who first spotted it.

PTF 11kly occurred in the Pinwheel Galaxy, located in the Ursa Major constellation, better known as the Big Dipper. At a distance of roughly 21 million light years, that puts it, on a cosmic scale, practically "in our backyard," Nugent said.

By comparison, most supernova found with the 48-inch Palomar telescope are about 1 billion light years away and far too faint for the general public to see, Nugent said.

Initially detected on August 24, the PTF 11kly has literally grown brighter by the minute and was already 20 times more luminous in just one day.

It is expected to reach its peak sometime between September 9 and 12, when it will become visible to stargazers using a good pair of binoculars or small telescope.

It will appear, bluish-white, just above and to the left of the last two stars in the Big Dipper handle.

"There are billions of stars in a galaxy. This supernova will outshine them all this weekend," Nugent told Reuters.

Supernovae of this type, classified as a "Type 1a" event, occur when a superdense white dwarf star, about the size of Earth but containing somewhat more mass than our own sun, explodes like a gargantuan thermonuclear bomb.

The blast hurls matter in all directions at nearly one-tenth the speed of light – matter that ultimately will form the building blocks of other stars and planets.

Such events, accounting for about one in five of all supernovae, are also used by scientists in measuring the expansion of the universe.

Similar supernovae are known to have occurred in the Pinwheel Galaxy at least three times before – in 1909, 1951 and 1970. But instruments available to observe this one are far more sophisticated, and its early detection is giving scientists an unprecedented glimpse of such phenomena.

For astronomers, the royal straight flush of supernovae are those occurring in our own galaxy, which last happened in 1572 and was visible with the naked eye for months, Nugent said.

Records from antiquity indicate that an even more spectacular supernova in the Milky Way lit up the sky in 1006 A.D., Nugent said. Telegraph