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Why is Betelgeuse glowing so brightly and behaving so strangely?

theguardian.com

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Re: Why is Betelgeuse glowing so brightly and behaving so strangely?

#51

Post by denton-scratch »

eimrine wrote: post #20
isaacfrond wrote: post #3

tl;dr Betelgeuse, the closest red giant star to Earth, is exhibiting unusual behavior. Normally, the star cycles between bright and dim states every 400 days. However, between late 2019 and early 2020, it went through a "great dimming" due to a dust cloud that obscured our view of the star. Currently, Betelgeuse is glowing at 150% of its normal brightness and is cycling between bright and dim states every 200 days, w…

> Betelgeuse is anticipated to explode as a supernova in the next 10,000 to 100,000 years. I would like Theguardian to expose a standard deviation for this kind of data (because I have read from other sources that nobody has the data, it easily may be tomorrow).

> it easily may be tomorrow

Tomorrow is in the next 10,000 to 100,000 years.

Re: Why is Betelgeuse glowing so brightly and behaving so strangely?

#52

Post by denton-scratch »

isaacfrond wrote: post #11

Wait a minute. If you emit material wouldn't you spin slower . Take the arm waving example from the article. Stand in the middle of the room and spin with you arms at your side. Now suddenly spread you arms. You will notice a marked reduction in rotation speed, not an increase. Who can explain this for me?

I don't think the pulsations are due to rotation. It grows and shrinks periodically, causing changes in absolute magnitude; and there seems to be more than one period. The various periods seem to be related harmonically.

Re: Why is Betelgeuse glowing so brightly and behaving so strangely?

#54

Post by djbusby »

candiddevmike wrote: post #6
belter wrote: post #4

Earlier quoted context omitted.

"Is Earth in danger if Betelgeuse goes supernova?" - https://www.skyatnightmagazine.com/space-science/earth-dange...

I hate articles filled with meandering fluff. The answer is buried 3/4 of the way down the page, and it's "No, it's too far away".

When headlines end with a '?' the answer is: No

Re: Why is Betelgeuse glowing so brightly and behaving so strangely?

#56

Post by belter »

raducu wrote: post #48
belter wrote: post #19

From this paper : "Spectroscopic evidence for a large spot on the dimming Betelgeuse" - https://arxiv.org/pdf/2108.03472.pdf "Evidence for a large cool spot: What could lead to a temperature drop by 170 K? It should be noted that the lowest temperature obtained on 31-01-2020, Teff = 3476 K, would be one of the coolest effective temperatures measured for a Galactic RSG... According to the stellar evolution theory, the…

But do we know if the amount of temperature drop is reasonable enough for a mass loss, or it's too great and automatically implies supernova?

I don't think anybody knows, but I am sure there is a Nobel prize at the end of that answer. In the meanwhile...

See "25.1 Main characteristics of massive star evolution" on this one: "Understanding Stellar Evolution" - https://www.hennylamers.nl/wp/wp-content/uploads/2014/10/Lam...

"Hayashi limit" - https://en.wikipedia.org/wiki/Hayashi_limit

Re: Why is Betelgeuse glowing so brightly and behaving so strangely?

#57

Post by psychphysic »

marktangotango wrote: post #43
h2odragon wrote: post #37

Earlier quoted context omitted.

Prosecute the astronomers for inaccuracy in their warnings. "Italian scientists convicted for not warning about deadly 2009 quake" https://www.cbsnews.com/news/italian-scientists-convicted-fo...

How did that turn out? Were they acquitted? I've noticed in other cases that Italian prosecutors seem have an unusual amount of latitude, or is that normal?

Depends who you know in some places.

Re: Why is Betelgeuse glowing so brightly and behaving so strangely?

#58

Post by psychphysic »

oskarkk wrote: post #46
marginalia_nu wrote: post #35

Earlier quoted context omitted.

Are you looking back far enough? Ancient Egypt really fucking ancient. Like it was about as ancient to classical antiquity as classical antiquity is to us now.

My favorite fact about timescales is that Cleopatra lived closer to the moon landings than to the building of pyramids.

What!?

Re: Why is Betelgeuse glowing so brightly and behaving so strangely?

#59

Post by yamtaddle »

psychphysic wrote: post #58
oskarkk wrote: post #46

Earlier quoted context omitted.

My favorite fact about timescales is that Cleopatra lived closer to the moon landings than to the building of pyramids.

What!?

The pyramids at Giza are really, really old.

Cleopatra was part of the Macedonian/Greek dynasty in Egypt, which comes basically at the tail end of what one might consider "ancient Egypt". The time span we lump together as "ancient Egypt" (specifically, dynastic ancient Egypt—"pre-dynastic" stretches back many centuries before that) is so long that stuff from the first third or so of it is farther, time-wise, from Cleopatra than the moon landings were.

Wikipedia:

> All [the three big pyramids at Giza] were built during the Fourth Dynasty of the Old Kingdom of ancient Egypt, between 2600 and 2500 BC.

Cleopatra is tied up with Julius Caesar and Antony (as in Shakespeare's Antony and Cleopatra) and all that happens just before the BC/AD transition, and these numbers are large and fuzzy enough we can just call her time 0. ~2500 years after the pyramids, ~1970 before the moon landings. Plus or minus a few years, but it doesn't make much difference.

Re: Why is Betelgeuse glowing so brightly and behaving so strangely?

#60

Post by FiatLuxDave »

nixass wrote: post #7

I'd really love to see major space event like Beetlegeuse blowing up during my insignificant life-span

Were you around in 1994? I was amazed that Shoemaker-Levy 9 happened in my lifetime.

https://en.wikipedia.org/wiki/Comet_Shoemaker%E2%80%93Levy_9

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