Are you ready for the “Blaze Star” to erupt? When T Coronae Borealis (T CrB) — a dim star in the constellation Coronoa Borealis — “goes nova” and becomes visible to the naked eye for a few weeks, it will be all over the media. You’ll read terrible headlines like “New star lights-up night sky” written by desk-bound reporters who know nothing about stargazing. Almost everyone on the planet will be taking a peek and mostly getting completely lost and confused.
However, if you get organized, do a little homework, and —most importantly — get outside and look up soon, you’ll be in with a chance of getting much more from a true once-in-a-lifetime celestial event. You can be among the few who can say you saw, appreciated, and understood how lucky you were to witness such a rare event.
Here’s everything you need to know to prepare for the “Blaze Star”/T Coronae Borealis/T CrB to go nova:
What Is The ‘Blaze Star’/T Coronae Borealis/T CrB?
Nicknamed the “Blaze Star,” T Coronae Borealis (T CrB) is a binary system — a star system like the solar system, but with two stars — in which one explodes every 80 years. This is not uncommon. Binary stars explode all the time — in cosmic time. Explosions could be multiple centuries apart, even more. In one average human lifetime, there is only one binary star system that does so, and that’s the “Blaze Star”/T Coronae Borealis/T CrB.
It could explode as soon as Thursday, March 27, surging in brightness from very dim and invisible to the naked eye to bright enough to see. This is what astronomers call a “nova” — a new star — that results from a rare stellar eruption.
What’s Happening On The ‘Blaze Star?’
Whatever we’re about to see has already happened. Since this star system of a white dwarf (the dense core of a dead star) and a red supergiant (an expanding cooling star) is 3,000 light-years away, whatever is about to happen did so 3,000 years ago. It’s just that the light is about to reach us. Shocked? Don’t be. Even the sunlight you feel on your skin is eight minutes old. Technically speaking, everything you see is old light — even when you look at the person next to you.
The “Blaze Star” is what’s known as a recurrent nova. When a white dwarf in a binary system sucks enough hydrogen from its red giant companion, it triggers a thermonuclear explosion. That process works almost like clockwork and results in a bright flash that has been seen every 80 years or so by previous generations of astronomers in 1786, 1866 and 1946‚ and now, almost certainly in 2025-2026. There are records going back to 1217.
When Will T CrB Explode?
It’s only roughly “every 80 years” because that figure doesn’t take into account the specific nature of the event that lasts only a few days — possibly a few weeks. We’ve had a few false alarms this time around, with some predictions pinpointing mid-2024. That’s based on dips in brightness before the big explosion, which were observed last time around. The latest research, which takes into account the fact that the two stars take 228 days to orbit each other, has the Blaze Star/T Corona Borealis/T CrB going nova on March 27 or November 10 in 2025, June 25, 2026, or February 8, 2027.
Where And How To See the Blaze Star
When it does go nova, the Blaze Star will appear in the Corona Borealis constellation — Latin for “Northern Crown.” This small crescent of seven stars is between the larger, more prominent constellations of Hercules and Boötes in the Northern Hemisphere. Here’s how to find it:
- Go outside at 10 p.m. tonight, wherever you are in the northern hemisphere.
- Find The Big Dipper high in the northwestern sky and follow the curve of its handle, taking an “arc to Arcturus,” a bright star above due east.
- Trace a line from Arcturus down to a bright star, Vega, close to the northeastern horizon.
- Halfway between the two is a curve of seven stars — Corona Borealis.
How Bright Will T CrB Be?
It’s thought that T CrB will reach an apparent magnitude of +2 when it finally explodes. That’s about the same as Polaris, the North Star, the 48th brightest star in the night sky. It should be clearly visible to the naked eye and will remain so for several days. However, unless you already know where Corona Borealis is and are familiar with its stars, it’s likely that this headline-grabbing nova will be somewhat underwhelming.
There’s going to be a lot of “is that it” commentary about this event from the kind of people who have no appreciation of how rare this event is. With this information, that won’t be you, because you’ll have already found, studied and be familiar with the constellation Corona Borealis‚ and maybe even spot it yourself when it does explode.
Wishing you clear skies and wide eyes.
