How many of us get a chance to witness a celestial event in our lifetimes? The recent total solar eclipse, which wowed North America and other parts of the world, was just one example.

But between now and September 2024, a star system, located 3,000 light-years away from us, is predicted to become visible to the unaided eye thanks to a thermonuclear explosion between its two stars.

According to US space agency Nasa, this could be a once-in-a-lifetime viewing opportunity as the “nova outburst” only occurs about every 80 years. T Coronae Borealis, or T CrB, last exploded in 1946 and astronomers believe it will do so again between February and September 2024.

The star system, normally magnitude +10, which is far too dim to see with the unaided eye, will jump to magnitude +2 during the event. This will be of similar brightness to the North Star, Polaris. “Once its brightness peaks, it should be visible to the unaided eye for several days and just over a week with binoculars before it dims again, possibly for another 80 years,” Nasa explains on its website.

What is the constellation Corona Borealis?

Corona Borealis is a relatively dim, small constellation in the Northern Celestial Hemisphere. It is also known as the Northern Crown — a small, semicircular arc near Bootes and Hercules. This is where the outburst will appear as a “new” bright star, Nasa explains on its website. Corona Borealis is one of the 48 constellations listed by the second century astronomer Ptolemy, and remains one of the 88 modern constellations.

How will the runaway nuclear reaction occur?

The binary star system has two objects: a red giant star and white dwarf that orbit each other. According to an AFP report, the two celestial objects are so close that matter being ejected by the red giant collects near the surface of the white dwarf.

“The stars are close enough that as the red giant becomes unstable from its increasing temperature and pressure and begins ejecting its outer layers, the white dwarf collects that matter onto its surface. The shallow dense atmosphere of the white dwarf eventually heats enough to cause a runaway thermonuclear reaction – which produces the nova we see from Earth,” Nasa’s website explains.

According to Nasa, this recurring nova is only one of five in our galaxy. It was first discovered in 1866 by Irish astronomer John Birmingham.

Also read: Astronomers discover oldest ‘dead’ galaxy ever observed