The Star Set to Explode Totally Flaked. Here’s What to Expect Next

Sky watchers were disappointed last night when a binary star system didn’t erupt in a nova explosion that was predicted to take place on Thursday. But fear not, the famous blaze star is still due for its recurring nova to erupt any day now.

The binary star system T Coronae Borealis (T CrB), also known as the Blaze Star, periodically explodes every 79 years or so, competing with the brightest stars in the night sky. A paper published last year predicted that the Blaze Star would erupt on March 27, building hope for a spectacular light show to brighten up our skies. Unfortunately, the recurring nova was a no-show on Thursday night, but the window for its explosion remains open, and there are two upcoming dates when it might take place.

The first recorded sighting of the T CrB nova happened more than 800 years ago, and the cycle repeats itself roughly once every 79 years on average. The last two previous explosions occurred in 1866 and 1946. The current window for the rare astronomical event opened in February 2024, and it’s still open, but astronomers aren’t sure exactly when the star system could go boom.

Astronomer Jean Schneider of the Paris Observatory published a paper last year in Research Notes of the American Astronomical Society, in which he combined the previous explosion dates with the orbital dynamics of the star system to pinpoint an exact date for the star system to explode. Schneider’s calculations landed on March 27, but he also listed two subsequent dates: November 10, 2025 and June 25, 2026.

It’s hard to predict when the star system will explode since its eruptions haven’t been observed that many times. Astronomers have been observing the Blaze Star, and found that it has spent the past decade behaving much like it did in the lead-up to its last visible eruption nearly 80 years ago, according to NASA.

Rather than relying on the behavior of the star, the recent study estimated that the nova eruptions occurred at intervals that were an exact multiple of the star system’s orbital period—meaning the explosions happened after a specific number of orbits the stars completed around each other. Schneider concluded that T CrB explodes once every 128 orbits, with each orbital period being roughly 227 days. But again, that’s just one researcher’s way of finding a pattern to the occurrences of the cosmos. To be clear, the system could explode later today, or next week, or a month from now, or as Schneider predicts, on November 10. We simply don’t know—we just know the explosion is imminent.

Located in the Corona Borealis constellation, T CrB is a binary system made up of a white dwarf (the remains of a dead star with a mass comparable to that of the Sun squeezed into an Earth-sized body) and an ancient red giant star. The red giant, roughly 1.12 times the mass of our Sun, orbits the white dwarf every 227 days. The two stars are separated by only 0.54 astronomical units, about the same as the distance from the Sun to Venus.

The red giant star is slowly being stripped of its hydrogen by the strong gravitational pull of its companion, the white dwarf, as the two are interlocked in a dangerous orbital dance. The material from the red giant star forms an accretion disk, which swirls around the white dwarf. As the hydrogen from the red giant star accretes onto the surface of the white dwarf, it causes a buildup of pressure and heat, which eventually triggers a thermonuclear explosion that blasts away all that material.

Unlike a supernova, which destroys a dying star, the dwarf star remains intact after the nova explosion. It does, however, blast the material into space in an explosive flash that’s bright enough to see from Earth with the unaided eye.

The star system itself is currently invisible to the unaided eye at a magnitude of +10. After its eruption, however, T CrB will be elevated to a magnitude of +2, almost as bright as the North Star. Although the outburst itself will be short-lived, the binary star system will twinkle bright in the night skies for a week or so before gradually fading back to its original brightness levels.

We’re just going to have to wait a little bit longer to see it happen before our eyes.