Blog

Seeing cosmic phenomena with the naked eye can be rare. So when someone introduces themselves, it’s a good idea to sit up and take notice. Like the recent solar eclipse and phenomena like the Aurora Borealis seen in our skies, there’s another dazzling event you’ll want to catch as soon as possible. It’s time to join the ranks of NASA scientists and astronomers waiting with baited breath for the cosmic explosion that will light up the night sky—and you don’t even need a telescope to see it.

Back in February 2016, astronomers broke the news that the T Coronae Borealis star system had entered a “phase of unprecedented high activity.” Eight years later, this solar activity could lead to another event large enough to be visible from Earth with the naked eye.

In a new event, a white dwarf star attracts solar material from a nearby red giant. When the heat and pressure become too high, the result is a thermonuclear explosion. This makes the white dwarf appear brighter in the sky, but it does not decay, and after the explosion dissipates, the star returns to its original brightness. This massive eruption is new.

The nova can be seen with the naked eye for more than a week after it occurs. For this period, it will appear that 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 could take longer.

What will the new one look like?

Those lucky enough to be watching the night sky when the show starts may be disappointed. It won’t look as explosive as it really is. According to Dr. Elizabeth Hayes, project scientist for the Fermi Gamma-ray Space Telescope at NASA’s Goddard Space Flight Center, someone looking up at the sky when the event occurs won’t see anything immediately.

“If they continue to watch for the next 24 hours, they will see a faint star emerge and gradually brighten,” Hayes told CNET. “Of course, someone on Earth will break their gaze, since the Earth is spinning.”

“The best time to look with the eye will be about a day after the eruption,” Hayes said. “But the new one will be visible for a few days.”

This NASA video shows what it looks like.

The last nova 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 is a binary star system consisting of a white dwarf and an ancient red giant about 3,000 light-years from Earth in the Northern Corona of the Milky Way. It is part of the constellation Corona Borealis, which makes a distinctive “C” shape in the sky, mostly during the summer months.

A 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, an aging red giant is a dying star that is spewing material into space. The massive gravitational pull of the white dwarf attracts the ejected material from the red giant. Once the white dwarf has accumulated enough material, the heat increases so much that it causes an uncontrollable fusion reaction. This explosion is called a nova.

The previous nova from this star system occurred in 1946. This is a cycle that has continued since it was first discovered more than 800 years ago.

“This is a once-in-a-lifetime event that will create many new astronomers, giving young people a cosmic event they can observe for themselves, ask their own questions and collect their own data,” said Rebecca Hounsell, assistant scientist fellow at NASA’s Goddard Space Flight Center. “This will feed the next generation of scientists.”

Where is the Corona Borealis?

You’re probably not as familiar with the Corona Borealis as you are with the easier-to-spot constellations like the Big Dipper. Hard to find in the night sky unless it’s clear. Light pollution from big cities can also make it difficult to find.

NASA says the easiest way to find the Corona Borealis is to find Vega and Arcturus, the two brightest stars in the Northern Hemisphere. (Skygazing apps for your phone can 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.

Alternatively, you can also look for the constellation Hercules and the Corona Borealis will be right next to it. Remember, you can’t see the star in question until the nova pops up, so if you look up in the sky before this happens, the spot where the nova will appear won’t be visible.

When will T CrB nova appear?

Nobody knows for sure. Astronomers and scientists only know that the nova should explode at any moment. Most of them agree that the new one should happen anytime before about September, although it could take longer.

Because the nova can appear at any moment, NASA relies on citizen astronomers and space enthusiasts to call it when the nova occurs.

“Using social media and email, (observers will) send instant alerts,” said Elizabeth Hayes, head of the Astroparticle Physics Laboratory at NASA Goddard. “We again rely on the global community’s engagement with T CrB.”

Early detection could also help NASA gather more data about the event to better understand its mechanics.

“We will observe the new event at its peak and through its decline as the visible energy of the outburst fades,” Hounsell said. “But it is just as important to obtain data during the early rise to eruption – so the data collected by these keen citizen scientists now looking for the nova will add dramatically to our findings.”

Do I need a telescope to see the new one?

No. NASA says the nova will be visible to the naked eye on a clear night. It will also be quite bright, so it should be quite noticeable. But as always, people with telescopes and binoculars will have a better view.

People with powerful telescopes will see the changes more clearly.

“A telescope that measures the optical spectrum will see something very different from the red giant’s spectrum,” Hayes said. They will see “nova flares emit spectral lines at certain wavelengths. They tell us about the elements in the explosion and how fast the blast wave is moving away from the white dwarf.”

The new one won’t look like an explosion like you see in Michael Bay movies. It will just look like another star in the sky that wasn’t there before.

What is the difference between a nova and a supernova?

Most people have heard of the term “supernova”. It is the last dying breath of a star as it dims. However, this final dying breath also turns out to be the largest explosion ever observed by humans, as the star furiously ejects material into space. Scientists believe that supernovae are responsible for the elements heavier than iron in the universe. Oddly enough, even the iron in your blood can be traced back to supernovae or similar cosmic explosions.

Nova, on the other hand, requires two stars. One star is always a white dwarf, while the other is usually a red giant.

There are other types of new ones. Hypernovae are supernovae that reach a certain size and brightness. They are usually about 10 or more times brighter than a standard supernova. Another type, the extremely rare kilonova, occurs when two neutron stars collide, releasing an incredible gravitational wave along with electromagnetic radiation.