Caoimhín's Content

Today we are going to be taking a look at a few different things in the sky, including the Blaze Star, T Coronae Borealis. While we’re at it, we’re going to be doing a little bit of complaining, or at least I’m going to be doing a little bit of complaining. I am going to need to move out to the countryside to begin with in order to see the constellation properly. There is a star in the constellation Corona Borealis that is visible from most cities, but with a dark sky it’s a lot easier to find the curved shape of the northern crown..

To start with, if you find Arcturus, Corona Borealis is nearby. As you may remember, you can follow the arc of the handle of the Plough or the Big Dipper down to Arcturus. Arcturus is the brightest star in Boötes, or Bootes, really it’s Boötes. The shape of Boötes is kind of like a kite. Arcturus is part of the tail and then, roughly north of Arcturus, is the sort of lozenge shape of the kite. Right next to that, with a fairly bright star forming a gem in the crown, we have the curved shape of Corona Borealis, the northern crown. If we could see the lines of the constellations, we would see the kind of lozenge shape and the kind of tail of the kite. With the images of the constellations we would see a little crown, that’s Corona Borealis.

We’ll zoom in a little bit, and bring up the boundary of the constellation. The boundary of a constellation doesn’t always fully align with its picture, and there are other stars within Corona Borealis’s boundary that aren’t part of the classic shape of the constellation. There’s actually quite a bit of room to the north which is considered part of Coronae Borealis. We’re looking for a particular star that isn’t quite visible to the naked eye, known as the Blaze Star. It’s also known as T Coronae Borealis, or T CrB for Coronae Borealis. The Blaze Star is its popular name, because it is a cataclysmic variable star. It is a double star as well, and not all double stars are cataclysmic variables, but this one is. There are two stars quite close together, a bigger and a smaller star, which I believe is really a white dwarf, it’s not quite a full star. The smaller star is close enough to the larger star that it’s able to pull down part of its atmosphere onto its surface, slowly build up material, and eventually go nova. Not supernova, just nova.

It is called a cataclysmic variable because the outer layer of the smaller star, the layer that builds up from the bigger star’s atmosphere, that does blow up entirely. It blows off and the whole process starts again. If the explosion, if the nova, is violent enough then it can destroy the smaller star. That does occasionally happen, but it doesn’t seem to have happened with this one yet. Currently it’s at magnitude 10.25, which isn’t quite visible to the naked eye, about 7th magnitude is really the limit of the eye under most conditions. This star is just to the side of the main shape of Corona Borealis. The main shape of Corona Borealis is a curve, with the brightest star Alphecca at the bottom. I referred to it as the jewel in the crown, that’s not an official name for it or anything like that. The Blaze star just inside the space that’s considered part of Corona Borealis., on the far side of the curve to Boötes. This star is presumably going to go nova soon. It went nova about 80 years ago, really about 79 years ago, and we were able to see it happen. The star went from this 10th magnitude star up to, I believe, about 5th or 6th magnitude, enough to be visible to the naked eye at least.

It certainly went from not being visible to our eyes to visible to our eyes under good conditions, but this is something that may not be visible from a city sky. It will be on the edge of visibility, so you may need to go out to the countryside to see it. However, people have been predicting the explosion of the Blaze Star since the 1940s. The prediction made in 1946, when the regular cyclical nature of these cataclysmic variable stars was really just beginning to be understood, was for a nova between 2026 and 2027. Unfortunately, and I think it is unfortunate, what happened around 2018 or so is that the star brightened. Brightening events such as that were recorded leading up to novas in the past, and that made people believe that the nova might come early. Fast forward to about 2023 and the star dimmed. Dimming had also preceded past novas, leading to more predictions. The roughly 10th magnitude at the moment, that magnitude isn’t constant. That magnitude is the product of light from two stars and so as their brightness changes, as they move around each other and eclipse each other, as atmosphere builds up on one star from another, that does change their apparent brightness in the sky. The magnitude we use is almost always the apparent magnitude. As you can see, the absolute magnitude is about 0.45, so it would be pretty bright if you were closer to it.

However, what matters is that the star hasn’t gone nova yet. A couple of things happened, the brightening followed by the dimming, that made people believe that it would happen sooner. People predicted this star going nova, suddenly becoming visible in the sky, in 2024, 2025 and in 2026. I myself made a video about the Blaze Star. If you search “Blaze Star” on this website or on the Caoimhín’s Content YouTube channel, you will find an article and a video where I discussed this star and how it was likely, proposed, predicted to go nova, but it still hadn’t. The most specific, precise, prediction that I have seen so far is 8th of February 2027. That is the most precise prediction that I have seen that hasn’t already turned out to be wrong, and it isn’t necessarily going to be accurate. We can’t know if a prediction is accurate until the event occurs, but it is precise. It’s not just saying it will happen in 2027, or the first part of 2027, or even February, it’s giving an exact date that we can look forward to, which is bold. By bold, I mean brave, it’s brave to make predictions like that. No doubt there are going to be newspaper titles saying “Get ready for the supernova”, or “Get ready for the nova”, once we get into 2027, once we get to February. In fact, I’m sure that around February 8th there will be newspaper titles saying “There will be a new star in the sky tonight!”. These predictions have failed, so far, every time. They’re going to be right eventually, this star will go nova, but it could be later in 2027. The cycle may not be exactly 80 years, there is a chance that the cycle slowly slows down over time and we haven’t seen it happen enough times to notice. Most of these predictions are almost destined to be inaccurate.

If we move forward first towards morning time and then a month or so into the future, Orion will rise. Betelgeuse is a star famous for the fact that it’s always about to explode. In the case of Betelgeuse, it would be a supernova, the collapse of a massive star at the end of its life. People have been saying that Betelgeuse is about to explode for ages, at least for decades, if not for hundreds of years. Our current estimate of the distance to Betelgeuse comes with a big margin of error, plus or minus 62.91 light years. That much of a margin of error makes it more difficult to say exactly what its absolute magnitude is. We’re saying minus five here, it would be a very bright star if we were closer to it, but this isn’t definite. It’s a double star and a pulsating variable star. The variable means it changes in brightness. The pulsating indicates something to do with the way it changes in brightness, not as cataclysmic as the other kind of variable. It gets brighter, it gets fainter. It is a double star, so we’re not looking at the brightness of just one star. The same thing with the Blaze Star, there is variability in brightness when we’re looking at these binary stars based on how the stars are lining up with each other. Of course, if one star’s brightness can fluctuate, two stars together have twice the potential to fluctuate in brightness. Where exactly Betelgeuse is is a little tough to know, and because that is a little bit tough, it’s tough to figure out exactly how old Betelgeuse is. It’s tough to figure out exactly when it’s going to pop. We have a much better idea of when the Blaze star is going to blaze, and it’s still not truly accurate.

I hope that we all get to see the Blaze Star going Nova in 2027. I hope we all see it on the 8th of February. I know that it will happen, I hope it happens soon, and I hope that not too many of you have been too disappointed by the waiting. I received a comment recently asking about the Blaze star, complaining about the fake news headlines saying that it was going to happen, that it was imminent. I agree, it is frustrating, and I’m sure in some small part I’m to blame. Afterall, I wrote a piece discussing it as well. I hope I was honest enough in that piece when I was explaining the difficulties of these predictions, the fact that it cannot be guaranteed. I really wanted to drive that homethis time, because we are still waiting for it, and once it happens, we don’t want to miss it. I very much hope that you enjoyed this piece. If you did, please do like it. If you enjoy this kind of content, then please subscribe to this website and my YouTube channel. Thank you very much for reading and hopefully I’ll see you back here next time.