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by pixel_tracing 1094 days ago
Fun fact: Betelgeuse has been predicted to go supernova in our lifetimes. There is usually a live stream on YouTube you can observe of Betelgeuse
5 comments

That’s not a very accurate way of saying "it could go supernova anytime in the next 100,000 years" meaning that it almost certainly won’t go during our lifetimes. Unless we’ll live for a long time which of course is not entirely out of the question.

Also, I’m pretty sure there’s no non-fake live stream of Betelgeuse on Youtube because it would require several robotic telescopes around the world programmed to coordinate and stream from wherever it’s a) night and b) Betelgeuse in the sky.

There's a pre-print (ie, not peer reviewed yet) study that, if correct, shows that the best-fit model for Betelgeuse's brightness oscillations over the past 30 years is that Betelgeuse is near the end of its carbon burning cycle. (doesn't have anything to do with the abnormal dimming in 2020 or so) If this study is correct (if) Betelgeuse will go supernova within 10-100 years.

The study: https://arxiv.org/pdf/2306.00287.pdf

youtube explanation (Dr Becky Smethurst) https://www.youtube.com/watch?v=3QgLwpuDGhI&t=415s

Already, this has rebuttals: https://twitter.com/lacalaca85/status/1666501987435700225 (link to a thread by author) and the paper itself: https://iopscience.iop.org/article/10.3847/2515-5172/acdb7a. (Note: RNAAS is not peer-reviewed, but there is a strict editorial standard; the arXiv thing is because of some long standing drama between arXiv and RNAAS).

The objections are primarily that the original paper assumes that a 2000 day period is the fundamental period of Betelguese's pulsation modes, which gives a radius that is much larger than what is observed in multiple wavelength bands.

It's unfortunate that Dr. Becky did not mention this in her video (perhaps it was published after she finished the script; even though it was out a while before the video was). I feel like this is not the first time that reputable science youtubers have jumped the gun on discussing research (Anton Petrov did something similar recently)

> doesn't have anything to do with the abnormal dimming in ~~2020~~ 2019 The Great Dimming is explained by this paper as being constructive interference of the pulsation modes (you can see this in their Figure 4. I don't know why Dr. Becky said this, but it doesn't seem to be correct.

Considering the scale of time for stars, I always read it as the lifetime of humans on Earth. Not our individual lifetimes. Like, Betelgeuse is so close to supernova that at some point in humanity's time on Earth we'll witness it. Other stars are millions to billions of years away from death that there's no point in considering it.
The problem is that it could also happen at any time in the next 10,000 to 100,000 years.
But, it could also happen tomorrow! I do hope it happens tomorrow, because that would be so cool.
I assume you're talking about this preprint study?

https://arxiv.org/pdf/2306.00287.pdf

Became aware of that one yesterday. This is one of the papers I have no hope of understanding myself. I'm hoping people with the right smarts will give it the thumbs up.

Would be nice event to catch.

https://en.wikipedia.org/wiki/Betelgeuse#Media_reporting

> Due to misunderstandings caused by the 2009 publication of the star's 15% contraction, apparently of its outer atmosphere, Betelgeuse has frequently been the subject of scare stories and rumors suggesting that it will explode within a year, and leading to exaggerated claims about the consequences of such an event. The timing and prevalence of these rumors have been linked to broader misconceptions of astronomy, particularly to doomsday predictions relating to the Mayan calendrical apocalypse. Betelgeuse is not likely to produce a gamma-ray burst and is not close enough for its X-rays, ultraviolet radiation, or ejected material to cause significant effects on Earth.

> Following the dimming of Betelgeuse in December 2019, reports appeared in the science and mainstream media that again included speculation that the star might be about to explode as a supernova – even in the face of scientific research that a supernova is not expected for perhaps 100,000 years. Some outlets reported the magnitude as faint as +1.3 as an unusual and interesting phenomenon, like Astronomy magazine, the National Geographic, and the Smithsonian.

> Phil Plait, in his Bad Astronomy blog, noting that Betelgeuse's recent behaviour, "[w]hile unusual . . . isn't unprecedented," argued that the star is not likely to explode "for a long, long time." Dennis Overbye of The New York Times agreed that an explosion was not imminent but added that "astronomers are having fun thinking about it.

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Evolutionary tracks for Betelgeuse https://arxiv.org/abs/1406.3143v2

> The best-fit MESA model left the main sequence about 10e6 yrs. ago, while for the EG model it was only about 3 × 10e5 years ago. Both models reached the base of the RGB about 40,000 years ago. We followed the star through the final ex- haustion of core helium burning in both codes, followed by brief epochs of core-carbon, neon, oxygen and silicon burning until core collapse and super-nova an age of 8.5 Myr since the ZAMS for the MESA code. Our best guess is that the star will supernova in less than ∼ 100, 000 yrs (even longer in the EG model). We note, however, that there error ellipse encompasses the entire track so that the star could be further along in its evolution. The constraint that it has passed the first dredge-up, however, means that the star is ascending the RSG phase. Our result is based upon mass loss from the base of the RGB is therefore a lower limit to how far it has evolved as a RSG.

What is the real one? Too many "happening now" :/