A striking astronomical event could light up the sky this week when a pair of stars bursts into a massive explosion.
The two-star system, called T Coronae Borealis (or T CrB) is located in the sky’s Northern hemisphere 3,000 light-years away from Earth.
It’s currently invisible, but astronomers say it will ignite in a burst of flame so bright that it will become visible to the naked eye for about a week. It’s expected to be as bright as the North Star, Polaris.
The star system only undergoes this dramatic transformation every 80 years.
‘It’s a once-in-a-lifetime event that will create a lot of new astronomers out there,’ Rebekah Hounsell, assistant research scientist at NASA’s Goddard Space Flight Center, said in a statement.
Astronomers can’t be sure of the exact date and time that the explosion will occur, but they have predicted that it will illuminate the night sky before the end of the month.
The T CrB star will be visible from Earth from 3,000 light-years away and is expected to shine as brightly as the North Star
To spot this cosmic wonder, step outside on a dark, clear night and look northeast.
You will want to be as far away from light pollution as possible, so if you live in the city, you may need to travel somewhere rural to see it.
If T CrB has ignited, it will appear in a faint constellation called the Northern Crown, or Corona Borealis, situated in a semicircular area between the constellations of Boötes and Hercules.
To help you locate this small patch of the night sky, you can start by finding the Big Dipper. Follow the curve of its ‘handle’ until you find a bright, reddish star above the eastern horizon.
That star is called Arcturus. From there, look directly northeast and you should see another bright star called Vega.
Halfway between Arcturus and Vega, you’ll find a faint curl of seven stars. This is the Northern Crown where T CrB will appear.
There is no way to know exactly when T CrB will ignite, so you may want to check multiple times throughout the week.
The T CrB system is comprised of a white dwarf – an Earth-sized remnant of a dead star with a mass roughly equal to the Sun’s – and an ancient red giant star.
The white dwarf star will emit a nova blast sometime before the end of the month
These two stars are locked in each other’s gravitational pull. But the red giant is slowly being stripped of its hydrogen by the force of its neighbor.
As the hydrogen from the red giant accretes on the white dwarf, it causes pressure and heat to build up.
The temperature and pressure on the red giant star increase from roughly 4,000 to 5,800 degrees Fahrenheit to more than 360,000 degrees Fahrenheit and causes T CrB to eject its outer layers that are collected on the white dwarf planet’s surface.
When the matter from the red giant reaches its maximum temperature, it sets off a nuclear reaction that creates an apocalyptic-type blast that releases 10,000 to 100,000 times the annual energy output of the sun.
This thermonuclear explosion is called a nova – not to be confused with a supernova, which is the final, enormous explosion that destroys some dying stars.
In a nova, the white dwarf remains intact, which allows this event to re-occur about every 80 years.
The most recent records of T CrB’s nova blast was in 1946 was in 1866, but reports indicate that observations occurred hundreds of years earlier.
Most nova explosions can last for thousands of years, but T CrB is unique in that it completes the full process in just a week.
When T CrB ignites, its brightness will peak and should be visible to the unaided eye for a little less than a week before it dims again, possibly for another 80 years, according to NASA.
