The Blaze Star T Coronae Borealis: A Nova Set to Explode Any Night in 2024

Star Walk
6 min readJun 17, 2024

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© Vito Technology, Inc.

Any moment now, a star that was hiding for decades will light up the night sky! A nova eruption is about to occur in the constellation Corona Borealis. That sounds big, and you might be expecting to see a full-sized explosion in the sky, but spoiler alert: the star in question, T Coronae Borealis (T CrB), will be just as bright as the North Star. Still, this is a fascinating event for astronomers and stargazers. Imagine: T CrB was last visible to the naked eye 80 years ago!

So, let’s keep an eye on this “new star.” It will also be easy to spot: just use our Star Walk 2 or Sky Tonight apps to guide you. We’ll give you all the details on how to make the most out of this historic event.

T Coronae Borealis recurrent nova

The event we’re so eagerly anticipating is called a nova, specifically a recurrent nova. Simply put, a nova is the sudden brightening of a star. And a recurrent nova is a nova that happens in cycles of a few decades or less. Don’t confuse it with a supernova, which is an explosion of a star when it dies.

For T Coronae Borealis, the cycle repeats every 80 years. The star tends to dim slightly for a year before an eruption, and it started dimming back in March 2023. So now, we’re waiting for the nova to happen any moment.

T Coronae Borealis nova event 2024

During the nova eruption, the star T Coronae Borealis will brighten from magnitude 10 to 2, which is visible to the naked eye. Here is what you need to know about this event.

When will the star explosion take place?

The exact date of the nova explosion is unpredictable, but scientists estimate it could occur anytime between now and September 2024. Astronomers and stargazers around the world are already closely monitoring T Coronae Borealis. Any change in the star’s brightness is recorded, and you can follow the T CrB thread on the AAVSO website, where stargazers share their observations. Be careful, however, as sightings may be inaccurate and should be double-checked. To save time, you can simply enable push notifications in our Star Walk 2 or Sky Tonight app. We will notify you as soon as it is confirmed that T Coronae Borealis has exploded.

Don’t be discouraged if you miss the moment of the explosion. The nova will be visible to the naked eye for several days, and may remain well-seen through binoculars for more than a week.

What will the nova look like?

T Coronae Borealis is expected to brighten up to magnitude 2 during the nova event, making it as bright as the North Star. Sadly (or luckily), we won’t see the eruption from the Earth. The star will look like an ordinary point of light, but it will join the pantheon of the 200 brightest stars in the sky! This is a big change from its current magnitude of 10, where it’s barely visible with high-powered binoculars. During the explosion, T Coronae Borealis will be easily seen with the naked eye for a few days.

Why does the star erupt?

T Coronae Borealis is actually a pair of stars: a white dwarf and a red giant. And their stellar relationship has its blazing moments! The white dwarf is the dense remnant of a star that has used up all its fuel, while the red giant is still active and heating up. As the red giant gets hotter and sheds its outer layers into space, the white dwarf pulls in that material. This causes the white dwarf to heat up and produce the increased brightness we see from the Earth as a nova.

Want to learn more about the stellar lifecycle? Check out our funny, cartoon-like infographic!

How to find T Coronae Borealis in the sky?

The much-anticipated nova, T Coronae Borealis, will appear in the constellation Corona Borealis, which can be a bit tricky to spot. This constellation looks like a small semicircle near Bootes and Hercules. Corona Borealis is best viewed from the Northern Hemisphere, reaching its highest point in the sky around July. For observers in the Southern Hemisphere, the constellation is more challenging to spot as it lies close to the northern horizon, but it is also best seen in July.

The brightest star in Corona Borealis is Alphecca, located in the middle of the semicircle. The nova will appear just below the bottom of this semicircle and should shine as brightly as Alphecca.

T Coronae Borealis is located in Corona Borealis, a small constellation best-seen in the Northern Hemisphere. It reaches the highest point in the sky in July. © Vito Technology, Inc.

To easily find the location of the upcoming nova, use our apps Star Walk 2 or Sky Tonight. Simply search for T Coronae Borealis, point your device at the sky, and follow the arrow until you see it on the app’s sky map. For now, you’ll only see darkness at that point, but how exciting it will be to witness a “new” bright star when the nova erupts! To make your experience more vivid, familiarize yourself with the constellation Corona Borealis beforehand.

Learn the location of Corona Borealis with Star Walk 2 or Sky Tonight and prepare for a new naked-eye star to appear there! © Vito Technology, Inc.

T Coronae Borealis in history

The T Coronae Borealis nova has been scientifically documented twice. It was noted by Irish astronomer John Birmingham on the night of May 12, 1866, and then again in 1946 by Leslie Peltier, the famed astronomer, author of the book “Starlight Nights.”

A recent study by Bradley Schaefer from Louisiana State University in 2023 suggests that a bright star was seen in the same region in 1217 and 1787. The Ursperger Chronicle of 1225 mentions that Abbott Burchard of Ursberg Abbey observed a “wonderful sign” in 1217. He noted that the mysterious object in the constellation Corona Borealis “shone with great light” for “many days.” The other sighting was recorded in a catalog published in 1789 by Reverend Francis Wollaston, an astronomer and clergyman.

FAQ

Are a nova and a supernova the same thing?

Novae and supernovae are distinct events, even though they share the Latin word “nova” (meaning “new”) in their names. A nova is a sudden, intense brightening of a star, increasing its brightness by 100 to 10,000 times. This occurs in binary star systems, where a white dwarf pulls matter from a companion red giant until a powerful nuclear fusion explosion happens on the dwarf’s surface. The star isn’t destroyed, and additional explosions can happen, known as recurrent novae.

In contrast, a supernova is a violent explosion that marks the end of a star’s life. Supernovae are far more brilliant than novae, often shining brighter than an entire galaxy for a brief period. If you want to learn more about the lifespan of stars, check out our colorful infographic.

Will the T Coronae Borealis nova damage the Earth?

T Coronae Borealis is a whopping 3,000 light-years away from us. At that distance, it poses no threat to the Earth. All we’ll see is the star brightening up to magnitude 2. A more spectacular event would be the Betelgeuse supernova explosion (though it’s unlikely to happen in our lifetime). But even that won’t pose any danger to us.

How long will T CrB be visible?

T Coronae Borealis is predicted to brighten from magnitude 10 to 2 in just a single day, or even within a few hours. It will stay visible to the naked eye for a few days, then will be viewable with binoculars for about a week before dimming back to its usual magnitude.

T Coronae Borealis: bottom line

T Coronae Borealis, a normally dim 10th magnitude star, is making headlines because it’s set to turn nova at any moment between now and September 2024. During this event, it will shine as brightly as the North Star. This is possibly a once-in-a-lifetime experience — the next time T Coronae Borealis will brighten up won’t be for another 80 years.

So, don’t miss out! Turn on push notifications in our Star Walk 2 and Sky Tonight apps, and we’ll alert you as soon as the nova arrives. Also, we recommend you to start observing the constellation Corona Borealis now and get familiar with its position in the sky. When the nova appears, you’ll be ready to locate it and witness this exciting celestial event!

Text Credit: Vito Technology, Inc.

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Star Walk
Star Walk

Written by Star Walk

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