You Might Have a Chance to Watch a Star Explode on March 27th

For the cosmos, grand, noteworthy events tend to happen with decades or centuries of downtime between them. For us humans, that means we often only get one chance to see some impressive spectacles. One such opportunity is upon us now—the star T-Coronae Borealis could have a nova soon.

A Star Could Go Nova on March 27th

T Coronae Borealis is a star with the nickname “Blaze Star.” That’s because it’s known for huge, sudden increases in brightness that occur roughly every 80 years or so. As luck would have it, the star is due for another explosion of brightness very soon. Now, before you get too excited, understand that March 27th is just one potential date that this celestial event could occur. It’s the earliest date that scientists are estimating based on previous eruptions from the Blaze Star.

This means that the star is not guaranteed to go Nova on March 27th, it’s just the earliest likely date that it could. If it doesn’t happen on that day, scientists estimate that it could also occur on November 10th of this year, or June 25th, 2026. Unfortunately, predicting stellar explosions is much less precise than things like moon phases and planetary alignments. But the Blaze Star has been erupting on a fairly regular schedule, with past explosions in 1946, 1866, and 1787.

Like I said though, predicting stellar phenomena is a lot of guesswork and estimation. March 27th is a rough date, so if you’re really interested in seeing this Nova, you might need to keep an eye out for it with a telescope for several days around that date. On that note, what exactly might you see? Novae are a specific type of stellar phenomenon, and they are often confused with their more extreme siblings.

The Difference in a Nova and a Supernova

The word “supernova” gets thrown around a lot more than just “nova.” You might assume these are just two words for the same thing, or even two closely related things, but they are quite different. In a supernova, the entire star is destroyed, exploding completely and possibly transforming into something else, like a black hole, if the star has sufficient mass for it.

To explain a nova, let’s talk about what type of star T Coronae Borealis is. It’s actually a binary star system, meaning there are two stars very close (relatively speaking) to one another. One is a red giant, and the other is a white dwarf. The white dwarf is close enough that it gradually accumulates material emitted from the red giant, which gathers on the white dwarf’s surface. The temperature and pressure on all of this material increases over time, until, eventually, there’s a thermonuclear reaction and it all blows up.

Naturally, this huge solar explosion makes the binary system much brighter for a brief window of time. The difference is so extreme that you can see the star with the naked eye during this time, which you can’t do ordinarily. How much brighter is the Blaze Star when this happens? Well, in 1946, the apparent magnitude of the star during its nova went from 10 to around 3. Yes, 3 is actually brighter than 10 on this scale.

Magnitude is a reverse logarithmic scale used to measure how bright stars are. Brighter objects have a lower magnitude number. Without getting into too much math, the brightness ratio between levels of magnitude is about 2.512 times. That means a magnitude 1 star is 2.512 times brighter than a magnitude 2 star, 6.31 times a magnitude 3 star, and so on. When the Blaze Star goes nova, it’s more than 600 times brighter than usual.

This is pretty impressive, considering that it’s nowhere near visible to the naked eye under normal circumstances. In fact, the faintest stars that can be seen by the human eye on a clear night are around magnitude 6.5, so the T Coronae Borealis system, normally a magnitude 10 star, would require a telescope to see. Light pollution can complicate stargazing a bit and make it harder to see some stars, but you can still stargaze even in light-polluted areas.

Where Should You Look to See the Blaze Star?

If you’re interested in seeing the nova eruption of T Coronae Borealis, you need to know where in the night sky to look for it. It’s part of the constellation known as the Corona Borealis, which you can find in the Northern Celestial Hemisphere. This means anyone who is North of the 50th Parallel South can see the entire constellation. That’s great news because unless you live on the absolute Southern tip of South America, the Antarctic, or a handful of tiny islands, you’ll be able to see it.

You can look to the bottom-most segment of Corona Borealis to see the Blaze Star when it goes off. That said, you’d be best served by a stargazing app that will help you locate constellations and stars, such as Google Sky, Stellarium, or Star Tracker. When you’re visually hunting for a speck of light in the night sky, a stargazing app makes it a whole lot easier to find it, and actually know that you found it.

Well, there you have it. Break out your binoculars, telescopes, or even your bare eyes and you just might catch a celestial phenomenon in the next few days. Just remember that the Blaze Star isn’t guaranteed to go nova and that no matter what happens, a cloudy sky could get in the way. Keep your hopes up, but manage your expectations too, just in case there’s a reason you don’t see it this week.