T Coronae Borealis Eruption: “Patience Is Key”
By Graham Jones. Published 10-Apr-2025
T CrB, also known as the Blaze Star, could explode “in the coming months or next year”—but, for now, things remain quiet.
T Coronae Borealis is composed of two stars: the white dwarf star on the left is “vampirizing” the red giant on the right. When the white dwarf accumulates too much material, it explodes. (Artist’s impression, based on Planquart et al. 2025.)
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Wait Goes On for the Blaze Star
Earlier this year, astrophysicist Léa Planquart talked to us about the uncertainties surrounding T Coronae Borealis (T CrB), a star system that is expected to explode sometime soon-ish.
We’re now into April—what’s the latest news on T CrB?
“Since then, the system has remained quiet,” Planquart tells us. “The explosion could occur in the coming months or next year. In this situation, patience is key!”
Where Will We See T Coronae Borealis?
When it explodes, the Blaze Star will be visible for a few days to skywatchers around the world. It will become one of the 50 brightest stars in the night sky—about the same brightness as Polaris, the North Star.
T CrB will appear next to Corona Borealis, a crown-shaped constellation from which it takes its name.
You can find and track T Coronae Borealis from your town or city using our Night Sky Map.
Show T Coronae Borealis on our Night Sky Map
You can use our Night Sky Map to follow the position of T Coronae Borealis as it moves across the sky.
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The Vampire Star
To recap, Planquart explained to us how T Coronae Borealis is actually two stars.
“One star is a cool red giant, about a hundred times larger than our Sun. The other is a white dwarf, of the size of Earth for a mass similar to the Sun.”
She also explained how the white dwarf is vampirizing its red giant companion.
“A nova explosion occurs when the white dwarf has accumulated too much material,” she said. “The pressure becomes so high it induces a thermonuclear explosion that blows the accumulated material away.”
Read more from our January 2025 interview with Léa Planquart
Ancient History
Fun fact: The explosion has already happened—about 3000 years ago.
There is a distance of roughly 3000 light years between T Coronae Borealis and Earth—which means that light from T CrB takes that long to reach us. (A light year is a measure of distance. It is the distance that light travels in a vacuum in exactly 365.25 days.)
Therefore, when we see the eruption happen, we’ll be watching ancient history: It actually took place 30 centuries ago, around the end of the Bronze Age in human history.