New visible star will be as bright as North Star in UK

A new star is due to burst into the night sky, shining as brightly as the North Star above Britain.

The explosion will happen in the constellation Corona Borealis, also known as the Northern Crown, which forms a semicircle of stars, which lies between Hercules and Boötes.

Although the white dwarf is currently invisible to the naked eye, it sits in a binary system where it has been sucking stellar material from its sister star and will soon erupt in a fiery nova explosion.

T Coronae Borealis, or T CrB, was last visible exploding in 1946 and Nasa believes it will be visible again at some point before September this year.

The star is currently 100 times fainter than it is possible to see with the naked eye, but will soon appear as bright as the North Star ‘Polaris’, blazing for around a week, before fading again.

Dr Mark Hollands, a research fellow from the University of Warwick’s Astronomy and Astrophysics group, said: “The ultra-dense white dwarf can steal material from the companion star in a process known as accretion, causing a layer of hydrogen to build up on the white dwarf surface.

“Once sufficient material has built up, this layer will reach a critical temperature, igniting hydrogen fusion.

“This powerful nuclear detonation ejects the gas from the white dwarf surface in a hot luminous shell. What we then see is the system becoming thousands of times brighter and is responsible for the observed nova.”

While most novae are unpredictable and seen only once, there are 10 known repeating systems which are termed recurrent novae.

Of these 10, T CrB is by far the closest at 3,000 light years away and is the only one with a sufficient peak brightness visible to the naked eye in areas with moderate light pollution.

It was first conclusively observed in an outburst in 1866 by Irish astronomer John Birmingham, with the most recent nova seen in February 1946.

In the months leading up to the 1946 explosion, astronomers noticed a pronounced drop in brightness, indicating an explosion was imminent, and there was a similar dip in February and March this year.

Dr Hollands said: “It signalled the fuse has been lit, and it is a matter of months before we witness the next nova.”

Although T CrB is too dim to be seen with the naked eye at the moment, it can be observed with a modest amateur telescope.

Once the eruption happens, no special equipment should be required, even in areas of moderate light pollution.

The star system, normally magnitude +10, will jump to magnitude +2 during the event.

“This could be a once-in-a-lifetime viewing opportunity as the nova outburst only occurs about every 80 years,” Nasa officials said in the statement.

Those wanting to spot the new star have been advised to get familiar with the patch of sky around the Corona Borealis constellation using a star chart, to learn which stars are currently visible.

“You’ll really appreciate the difference when one night in the next few months there is one extra member of the constellation,” added Mr Hollands.

“The nova will be visible to the naked eye for a few nights and reach a similar brightness to other stars in the Corona Borealis constellation, but if you miss that window, it’ll still be visible for a few weeks with a good pair of binoculars.

Since T CrB is around 3,000 light years away, the nova outburst will have occurred thousands of years ago.

In that time, T CrB will have undergone 35-40 more outbursts with all of their light signals still on the way.