Get Ready to See a Sky Explosion That Only Happens Once Every 80 Years – CNET
Every 80 years, the skies grant us a rare gift: a stellar explosion called a nova that outshines all other cosmic wonders. This celestial fireworks show occurs when a white dwarf star erupts, increasing its brightness ten thousandfold. Even with the naked eye, we can revel in its glory from millions of miles away, and another show is about to start very soon. NASA scientists and astronomers are waiting patiently to see it, just like we’ve yearned to see solar eclipses and the Aurora Borealis over the past few years.
In a nova event, a white dwarf star pulls in solar material from a nearby red giant. When the heat and pressure from this get too high, the result is a thermonuclear explosion. That makes the white dwarf appear brighter in the sky, but it doesn’t disintegrate, and once the explosion dissipates, the star goes back to its original brightness. That massive eruption is a nova.
The nova can be seen with the naked eye for upward of a week after it happens. For that period of time, it’ll seem like a new star has appeared in the sky. According to NASA, the explosion could happen anytime, day or night, between now and September, although scientists say it may take longer.
This NASA video shows what it looks like.
Last one from this star system was in 1946
The cosmic light show is courtesy of T Coronae Borealis, also known as the Blaze Star or T CrB. It’s a binary star system comprised of a white dwarf and an ancient red giant about 3,000 light years away from Earth in the Northern Crown of the Milky Way. It’s part of the Corona Borealis constellation that makes a distinctive C-shape in the sky, primarily during the summer months.
The white dwarf, which is the dead remnant of a star, is about the size of Earth but has the same mass as the sun. Meanwhile, the aging red giant is a dying star that’s shedding material out into space. The white dwarf’s massive gravitational pull is hauling in the ejected material from the red giant. Once the white dwarf has accumulated enough material, the heat increases so much that it causes a runaway thermonuclear reaction. That explosion is called a nova.
The prior nova from this star system occurred in 1946. It’s a cycle that’s been going on since it was first discovered more than 800 years ago.
“It’s a once-in-a-lifetime event that will create a lot of new astronomers out there, giving young people a cosmic event they can observe for themselves, ask their own questions, and collect their own data,” said Dr. Rebekah Hounsell, an assistant research scientist at NASA’s Godard Space Flight Center. “It’ll fuel the next generation of scientists.”
Where is Corona Borealis?
You likely aren’t as familiar with Corona Borealis as you are with constellations that are easier to spot, like the Big Dipper. It’s difficult to find in the night sky unless it’s clear. Light pollution from major cities can also make it more difficult to find.
NASA says the easiest way to find Corona Borealis is to find Vega and Arcturus, the two brightest stars in the Northern Hemisphere. (Skygazing apps for your phone might help with this.) From there, you can essentially draw an imaginary line between the two. Corona Borealis is almost right in the middle. You can use the graphic below to see what we mean.