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General => General Technical Chat => Topic started by: cleanworkbench on January 24, 2020, 04:39:08 pm

Title: Betelgeuse the star
Post by: cleanworkbench on January 24, 2020, 04:39:08 pm
What,s going on with this star Betelgeuse  , went outside my door last evening and its disappeared , big bang or what ?.
Title: Re: Betelgeuse the star
Post by: donotdespisethesnake on January 24, 2020, 05:05:43 pm
It would be awesome if it did, but quite unlikely.

We will detect neutrinos first before anything in visible light, so hopefully we would get a heads up. The initial explosion causes a "small" flash, the real brightness occurs for several days afterwards as the resulting gas cloud radiates.
Title: Re: Betelgeuse the star
Post by: edy on January 24, 2020, 05:11:42 pm
Let's just hope it's ejection beam isn't pointed directly at us. :-)  Is there any way to figure out the rotation axis of that star, or any distant star for that matter? Star Wars Death Star planet-killer comes to mind.
Title: Re: Betelgeuse the star
Post by: donotdespisethesnake on January 24, 2020, 05:13:22 pm
Wait and find out? :)

Title: Re: Betelgeuse the star
Post by: jaromir on January 24, 2020, 07:32:03 pm
Most astronomers expects Betelgeuse to go supernovae in (astronomically) very very short time, perhaps 50 or 100 thousands of years.
Title: Re: Betelgeuse the star
Post by: IanB on January 24, 2020, 07:37:01 pm
What,s going on with this star Betelgeuse  , went outside my door last evening and its disappeared , big bang or what ?.

Observations have shown it getting dimmer recently. Nobody knows why.

Most astronomers expects Betelgeuse to go supernovae in (astronomically) very very short time, perhaps 50 or 100 thousands of years.

Apparently some recent research suggests Betelgeuse may be different than first supposed and as such would be very stable and not likely to explode after all.
Title: Re: Betelgeuse the star
Post by: jmelson on January 24, 2020, 07:43:35 pm
Let's just hope it's ejection beam isn't pointed directly at us. :-)  Is there any way to figure out the rotation axis of that star, or any distant star for that matter? Star Wars Death Star planet-killer comes to mind.
Yes, it is nearly 90 degrees to us, so no worry.  That issue was thought of a long time ago and checked.

But, yes, while Betelgeuse is a known variable, in the last several hundred years of observation, it has NEVER dimmed anywhere this far.
"Something" is definitely up with it!

Jon
Title: Re: Betelgeuse the star
Post by: jaromir on January 24, 2020, 07:52:30 pm
Just to illustrate the thing, here is light curve of Betelgeuse - that is graph of apparent magnitude versus time.
It's red giant variable star, with main period of roughly 180 days. Currently its apparent magnitude is somehow similar to Bellatrix in right shoulder of Orion constellation.
I'm not holding my breath.
Title: Re: Betelgeuse the star
Post by: David Hess on January 24, 2020, 08:48:53 pm
https://science.slashdot.org/story/20/01/18/1632230/whats-up-with-betelgeuse
Title: Re: Betelgeuse the star
Post by: RoGeorge on January 24, 2020, 10:36:37 pm
Maybe Betelgeuse shines normally, but we are witnessing the born of a Type II civilization.
;D

https://en.wikipedia.org/wiki/Kardashev_scale

Title: Re: Betelgeuse the star
Post by: David Hess on January 24, 2020, 11:20:07 pm
Maybe Betelgeuse shines normally, but we are witnessing the born of a Type II civilization.
;D

https://en.wikipedia.org/wiki/Kardashev_scale

That would be doubly impressive around a star the size of Betelgeuse.  I think we can discount that possibility because nobody would be dumb enough to use a star so close to the end of its life.  Could that be why we cannot find as many red dwarfs as there should be?

Title: Re: Betelgeuse the star
Post by: donotdespisethesnake on January 24, 2020, 11:26:58 pm
Well, I would practice on a nearby star first, instead of our own. You know, just in case something "goes wrong" :)
Title: Re: Betelgeuse the star
Post by: edy on January 26, 2020, 02:20:40 am
They are working on a Dyson Sphere:

https://en.m.wikipedia.org/wiki/Dyson_sphere (https://en.m.wikipedia.org/wiki/Dyson_sphere)

(http://d3adcc0j1hezoq.cloudfront.net/wp-content/uploads/2016/09/dyson.jpg)

See this article:

http://midnightinthedesert.com/astronomers-just-found-second-dyson-sphere-star-dimming-brightness/ (http://midnightinthedesert.com/astronomers-just-found-second-dyson-sphere-star-dimming-brightness/)
Title: Re: Betelgeuse the star
Post by: Gyro on January 26, 2020, 11:20:55 am
I know a Dyson sphere is all about maximising energy capture but the thing I've never got is what do you do with the actual people?  :-//

Planetary atmosphere is held on by gravity. The 'floor' of a Dyson Sphere (necessarily) doesn't have enough mass to hold an atmosphere on the inside, the strongest gravitational force is generated by the star itself. Exit atmosphere, the same applies to objects and people!

You could make the sphere double walled with living quarters between (a pretty miserable existence) but again where do you get workable gravity. The Star's gravity wouldn't be enough to hold you comfortably to the inner floor.

You can't spin a sphere... well you can, but not in any way that equalizes centripetal force over the surface - there's going to be an awful lot of unusable uphill, both for atmosphere and ability to walk up it.

Now Larry Niven's Ringworld (or a Dyson ring) I do get. You can spin it at a sensible speed to generate 'gravity' and retan the atmosphere between high rim walls. Of course you still have to worry about maintaining stability etc. but at least you have somewhere to put your population. And people won't blunder into you in the dark.

Dyson sphere: There, finished it! Err, who turned the light out?..... Damn!
Title: Re: Betelgeuse the star
Post by: GlennSprigg on January 26, 2020, 12:43:24 pm
Betelgeuse is (was?) a Giant, but not particularly Hot. There is no particular reason why
it's mass should 'collapse' into a Super Nova etc. (Of course it may have died out a long time ago!).
Our own gaseous 'Jupiter' could/should have been another 'Sun' but wasn't big enough to 'ignite'.
Farewell Betelgeuse!!!   :scared:
Title: Re: Betelgeuse the star
Post by: David Hess on January 27, 2020, 11:00:08 am
Betelgeuse is (was?) a Giant, but not particularly Hot. There is no particular reason why
it's mass should 'collapse' into a Super Nova etc. (Of course it may have died out a long time ago!).

Betelgeuse is in its helium burning stage so its core is very hot and small which is why the outer envelope is so large.  There is every reason to expect it to become a supernova and produce a neutron star in the next 100,000 years at the soonest but consider that that is 50 times longer than recorded history so do not hold your breath waiting for it.

Quote
Our own gaseous 'Jupiter' could/should have been another 'Sun' but wasn't big enough to 'ignite'.

Jupiter is not even large enough to be a brown dwarf which can be distinguished by lack of lithium which gets fused in a significantly larger gas giant.
Title: Re: Betelgeuse the star
Post by: imo on January 27, 2020, 12:10:54 pm
It would be great if it explodes next weeks. I always wanted to see exploding supernova..  8)
CNN wrote they detected gravitational waves 2w back.
https://edition.cnn.com/2020/01/25/world/betelgeuse-star-dimming-scn-trnd/index.html
Quote
Then, LIGO, the Laser Interferometer Gravitational-Wave Observatory, detected gravitational waves on January 14 that seemed to come from the direction of Orion.
Does the LIGO detector actually work reliably?
Title: Re: Betelgeuse the star
Post by: nctnico on January 27, 2020, 12:31:34 pm
It would be great if it explodes next weeks. I always wanted to see exploding supernova..  8)
Same here. Would be awesome if it is close enough to get a bit of summer in the winter  :popcorn:
Title: Re: Betelgeuse the star
Post by: TERRA Operative on January 27, 2020, 01:13:50 pm
Mmmmmm gamma ray burst. Makes my bones smell like burning. Good tan though (on my bones that is).
Title: Re: Betelgeuse the star
Post by: Gyro on January 27, 2020, 01:46:48 pm
It would be great if it explodes next weeks. I always wanted to see exploding supernova..  8)
Same here. Would be awesome if it is close enough to get a bit of summer in the winter  :popcorn:

Well I hope it waits until it stops raining and we have clear skies - June would be about right!  :D
Title: Re: Betelgeuse the star
Post by: imo on January 27, 2020, 08:23:28 pm
It is 700ly off, problems for us start at 50ly and less, afaik..
From April up it moves closer to Sun, we will see nothing.
Title: Re: Betelgeuse the star
Post by: Alex Eisenhut on January 28, 2020, 08:16:09 am
Now Larry Niven's Ringworld (or a Dyson ring) I do get. You can spin it at a sensible speed to generate 'gravity' and retan the atmosphere between high rim walls. Of course you still have to worry about maintaining stability etc. but at least you have somewhere to put your population. And people won't blunder into you in the dark.

Well sure, except for the non-existent materials and need for stabilizers... But you put enough Protectors on the job I guess they'll find solutions.
Title: Re: Betelgeuse the star
Post by: CatalinaWOW on January 28, 2020, 07:28:34 pm
Any civilization that could put a shell around a star could solve trivial problems like this.  Keeping the atmosphere in just means making two shells two hundred kilometers apart or so.  And then find enough gas to fill the space.  Or maybe just make an earth sized bump on a stick with spin bearings to let it turn once every day or so.  There would be room on the inside of the sphere to put many thousand such bumps with PLENTY of elbow room between them.

Don't have to worry about us humans pulling off something like that for a long, long time.  Even if we do hit the "singularity".
Title: Re: Betelgeuse the star
Post by: thinkfat on January 28, 2020, 09:20:04 pm
Now Larry Niven's Ringworld (or a Dyson ring) I do get. You can spin it at a sensible speed to generate 'gravity' and retan the atmosphere between high rim walls. Of course you still have to worry about maintaining stability etc. but at least you have somewhere to put your population. And people won't blunder into you in the dark.

Well sure, except for the non-existent materials and need for stabilizers... But you put enough Protectors on the job I guess they'll find solutions.

I seem to remember that in "Ringworld: Engineers" it was found that the Ringworld was unstable because natives stupidly dismantled the attitude jets on the rim walls, throwing the Protectors into a frenzy to save the remaining inhabitants.
Title: Re: Betelgeuse the star
Post by: rdl on January 28, 2020, 11:08:52 pm
Now you guys have done it. I'm gonna have to drag all my old Niven books out of storage and read 'em again.
Title: Re: Betelgeuse the star
Post by: thinkfat on January 28, 2020, 11:31:57 pm
Sounds like a good plan.
Title: Re: Betelgeuse the star
Post by: Nominal Animal on January 29, 2020, 06:14:49 am
Now you guys have done it. I'm gonna have to drag all my old Niven books out of storage and read 'em again.
Draco Tavern short stories are my favourite, followed by Moties series (The Mote in God's Eye, King David's Spaceship, The Gripping Hand, and Outes).
Title: Re: Betelgeuse the star
Post by: David Hess on February 01, 2020, 03:10:12 am
It would be great if it explodes next weeks. I always wanted to see exploding supernova..  8)

I was reading up on red giant stellar evolution and it should do a lot more than dim before it goes supernova.

I seem to remember that in "Ringworld: Engineers" it was found that the Ringworld was unstable because natives stupidly dismantled the attitude jets on the rim walls, throwing the Protectors into a frenzy to save the remaining inhabitants.

I do not think it was ever made clear why the resident goul protector, Cronus, allowed the City Builders to steal the rimwall attitude jets.  I assume it was Cronus because Halrloprillalar said she was not familiar with Fist of God which was formed soon after Cronus was killed by the vampire Protectors Bran and Anne.  So Prill's people were stealing the attitude jets before that point.

Bran and Anne did not fix the situation even when the Ringworld started sliding off center but since they were non-sentient as breeders, they were not the brightest of Protectors although apparently bright enough not to be trapped or killed by Teela Brown who suspected or knew at least of Bran's existence in the Repair Center.
Title: Re: Betelgeuse the star
Post by: Alex Eisenhut on February 07, 2020, 11:24:06 pm
Now you guys have done it. I'm gonna have to drag all my old Niven books out of storage and read 'em again.

You know, I find A Gift From Earth enjoyable. World of Ptaavs is also a nice one.

My favorite stand-alonish novel is Protector.

I like his early stuff. Quick, fun, to the point, done.
Title: Re: Betelgeuse the star
Post by: Rick Law on February 09, 2020, 04:29:29 am
Don't worry about Betelgeuse.  With just 60 Starlink satellites launched, they are already causing huge problems for astronomers.  When SpaceX finish lauching 30,000 Starlink satellites, whether Betelgeuse is there or not, you will hardly ever see it or any other stars again.

For some reason, their construction made the satellites very reflective, so it is leaving huge light streaks (on photos) as they travel.  Their brightness is over-powering bright stars let alone dimmer ones.  The problem was identified after the first couple of launches (reference 3), yet by now there are about 60 up there with the same problem...

Attached is a photo (from reference#1) of how these damn satellite-streak looks with mere 60 sats.  Multiply that by 500 (for 30,000 satellites), you can see and how disruptive they are to the view of the sky even for mere star watchers let alone astronomers.

Reference:

1. KXAN (Austin, TX) NBC News: What was that streak of light across the night sky?  (source of the attached photo)
https://www.kxan.com/weather/weather-blog/what-was-that-streak-of-light-across-the-night-sky/ (https://www.kxan.com/weather/weather-blog/what-was-that-streak-of-light-across-the-night-sky/) 

2. Space Flight Now: Documents suggest SpaceX may launch 30,000 more Starlink satellites
https://spaceflightnow.com/2019/10/15/documents-suggest-spacex-may-launch-30000-more-starlink-satellites/ (https://spaceflightnow.com/2019/10/15/documents-suggest-spacex-may-launch-30000-more-starlink-satellites/)

3. Phy.Org: Astronomers say SpaceX's satellites are too bright in the sky. Friday's launch will try to fix that
https://phys.org/news/2020-01-astronomers-spacex-satellites-bright-sky.html (https://phys.org/news/2020-01-astronomers-spacex-satellites-bright-sky.html)
Title: Re: Betelgeuse the star
Post by: David Hess on February 09, 2020, 04:39:09 am
Now you guys have done it. I'm gonna have to drag all my old Niven books out of storage and read 'em again.

You know, I find A Gift From Earth enjoyable. World of Ptaavs is also a nice one.

My favorite stand-alonish novel is Protector.

I like his early stuff. Quick, fun, to the point, done.

I always thought Protector would make an excellent movie but it would take a good music composer.  It could start with a pull out from Phssthpok's eye as he watches his fusion flame and end with a pull out from Truesdale's eye as he composes his letter to Earth.

You might like the non-canon follow up stories to Protector by Matthew Joseph Harrington in the later Man-Kzin war books.  I think they make more sense than Niven's Ringworld prequels as far as the Pak and they tie up many Known Space plot lines.  Niven never said what ultimately happened to Roy Truesdale and the Home Protectors.

The Man-Kzin novel Destiny's Forge by Paul Chafe is excellent if you can put up with a retelling of the plot from Dune.
Title: Re: Betelgeuse the star
Post by: Alex Eisenhut on February 09, 2020, 05:12:16 pm
A World Out f Time would be good too.

For Protector, you'd need to expose the entire back-story of what a Protector is, the relationship to humans, how single-minded and smart and quick and strong they are, why they need Tree Of Life, why they'd come here sub-light, and what kind of havoc they would wreak.

World of Ptaavs relies on 1960s-1970s fascination with ESP which would not work well today.
Title: Re: Betelgeuse the star
Post by: David Hess on February 09, 2020, 11:50:02 pm
For Protector, you'd need to expose the entire back-story of what a Protector is, the relationship to humans, how single-minded and smart and quick and strong they are, why they need Tree Of Life, why they'd come here sub-light, and what kind of havoc they would wreak.

Conveniently the story already includes that in Phssthpok's flashbacks.  Later Truesdale discusses it with Nick and Garner although Truesdale was an unreliable narrator from the start.  Not everything has to be explained, just enough.

The whole plot just does not work at least if only canon Known Space stories are included but that is no worse than practically all Hollywood science fiction.  The original assumption about humans not being native to Earth is just wrong.  The Protector stories by Matthew Joseph Harrington that I mentioned earlier address this directly which is why I prefer them as an alternative.
Title: Re: Betelgeuse the star
Post by: Mr. Scram on February 10, 2020, 12:14:46 am
Betelgeuse is in its helium burning stage so its core is very hot and small which is why the outer envelope is so large.  There is every reason to expect it to become a supernova and produce a neutron star in the next 100,000 years at the soonest but consider that that is 50 times longer than recorded history so do not hold your breath waiting for it.

Jupiter is not even large enough to be a brown dwarf which can be distinguished by lack of lithium which gets fused in a significantly larger gas giant.
Interestingly Jupiter is roughly as big as planets get. They can get heavier but compress that mass into similar or smaller spaces until they become a brown dwarf or star. There are larger planets but these hot Jupiters tend to be very close to their stars and are consequently hot and have swollen to very low densities.
Title: Re: Betelgeuse the star
Post by: David Hess on February 10, 2020, 01:08:28 am
Betelgeuse is in its helium burning stage so its core is very hot and small which is why the outer envelope is so large.  There is every reason to expect it to become a supernova and produce a neutron star in the next 100,000 years at the soonest but consider that that is 50 times longer than recorded history so do not hold your breath waiting for it.

Jupiter is not even large enough to be a brown dwarf which can be distinguished by lack of lithium which gets fused in a significantly larger gas giant.

Interestingly Jupiter is roughly as big as planets get. They can get heavier but compress that mass into similar or smaller spaces until they become a brown dwarf or star. There are larger planets but these hot Jupiters tend to be very close to their stars and are consequently hot and have swollen to very low densities.

Just going by memory, the distinction between gas giants and brown dwarfs is whether enough mass is present allow the fusion of residual lithium from the time of formation.  So Jupiter has lithium present and a brown dwarf, which will have more mass, does not because the lithium was used up in fusion which has since stopped because the mass is not enough to fuse hydrogen.

Title: Re:Betelgeuse the star
Post by: krupski on February 10, 2020, 07:22:05 am
Let's just hope it's ejection beam isn't pointed directly at us. :-)  Is there any way to figure out the rotation axis of that star, or any distant star for that matter? Star Wars Death Star planet-killer comes to mind.

Betelgeuse rotational axis is about 20 degrees off pointing directly at us. Of course we don't know what kind of gyrations it may make as it's collapsing.

Whats very interesting is that Betelgeuse has recently dimmed significantly. Occlusion by dust, or ready to blow?

We'll know when there is a blazing bright spot in Orion, that fades away over the course of a few months.

Title: Re: Betelgeuse the star
Post by: Alex Eisenhut on February 11, 2020, 12:12:47 am
The Man-Kzin novel Destiny's Forge by Paul Chafe is excellent if you can put up with a retelling of the plot from Dune.

One author I like is Donald Kingsbury. Dude can write. He played around in the Foundation universe (unauthorized) with the book Psychohistorical Crisis. It's great! He also tooled around in Known Space.
Title: Re: Betelgeuse the star
Post by: Nominal Animal on February 11, 2020, 03:46:11 am
Has anyone else read Edward T Yeatts III's Lords of Kobol (http://www.ety3rd.com/8652.html) series, a free fan prequel/background to Battlestar Galactica and Caprica?  I found them entertaining.
Title: Re: Betelgeuse the star
Post by: coppercone2 on February 13, 2020, 08:15:06 am
I refuse to go outside and look. Maybe there was a star maybe there was no star to begin with. Not my business. I keep my hands clean of politics. I do believe there should be a compensation for the energy lost however, based on all the decisions and calculations that occurred with the idea that the star had existed, in order to keep deals in a favorable light.

This has an quality effect on solar power manufacturers and gravitational lensing systems capabilities.
Title: Re: Betelgeuse the star
Post by: RoGeorge on February 17, 2020, 07:33:27 am
(https://apod.nasa.gov/apod/image/2002/Betelgeuse2019_ESO_1280.jpg)

Source
https://apod.nasa.gov/apod/astropix.html

 :-//
Title: Re: Betelgeuse the star
Post by: jaromir on February 17, 2020, 09:13:28 am
Majority of people are worried about Betelgeuse, astronomers are rejoicing the extended holidays, because usually you can't directly observe variable star going so much variable in such a detail.

For anyone interested in visualizing some measured data:
1, AAVSO (American Association of Variable Star Observers - https://www.aavso.org/ (https://www.aavso.org/) ) does have tool to plot light curves, in particular for Betelgeuse it looks like this
https://www.aavso.org/lcg/plot?auid=000-BBK-383&starname=BETELGEUSE&lastdays=200&start=&stop=2458896.87343&obscode=&obscode_symbol=2&obstotals=yes&calendar=calendar&forcetics=&pointsize=1&width=800&height=450&mag1=&mag2=&mean=&vmean=&grid=on&visual=on&uband=on&bband=on&v=on (https://www.aavso.org/lcg/plot?auid=000-BBK-383&starname=BETELGEUSE&lastdays=200&start=&stop=2458896.87343&obscode=&obscode_symbol=2&obstotals=yes&calendar=calendar&forcetics=&pointsize=1&width=800&height=450&mag1=&mag2=&mean=&vmean=&grid=on&visual=on&uband=on&bband=on&v=on)

2, Amateur astronomer Michael Hippke created twitter bot to pull data from AAVSO sources, process and post updates. It's open source, available here https://github.com/hippke/betelbot (https://github.com/hippke/betelbot) ; live version on twitter is here https://twitter.com/betelbot (https://twitter.com/betelbot)
Title: Re: Betelgeuse the star
Post by: paulca on February 17, 2020, 01:14:16 pm
You have to say his name three times didn't you?

(https://vignette.wikia.nocookie.net/moviedatabase/images/a/ac/Betelgeuse.jpg/revision/latest?cb=20140219203235)
Title: Re: Betelgeuse the star
Post by: coppercone2 on February 17, 2020, 11:18:29 pm
Don't worry about Betelgeuse.  With just 60 Starlink satellites launched, they are already causing huge problems for astronomers.  When SpaceX finish lauching 30,000 Starlink satellites, whether Betelgeuse is there or not, you will hardly ever see it or any other stars again.

For some reason, their construction made the satellites very reflective, so it is leaving huge light streaks (on photos) as they travel.  Their brightness is over-powering bright stars let alone dimmer ones.  The problem was identified after the first couple of launches (reference 3), yet by now there are about 60 up there with the same problem...

Attached is a photo (from reference#1) of how these damn satellite-streak looks with mere 60 sats.  Multiply that by 500 (for 30,000 satellites), you can see and how disruptive they are to the view of the sky even for mere star watchers let alone astronomers.

Reference:

1. KXAN (Austin, TX) NBC News: What was that streak of light across the night sky?  (source of the attached photo)
https://www.kxan.com/weather/weather-blog/what-was-that-streak-of-light-across-the-night-sky/ (https://www.kxan.com/weather/weather-blog/what-was-that-streak-of-light-across-the-night-sky/) 

2. Space Flight Now: Documents suggest SpaceX may launch 30,000 more Starlink satellites
https://spaceflightnow.com/2019/10/15/documents-suggest-spacex-may-launch-30000-more-starlink-satellites/ (https://spaceflightnow.com/2019/10/15/documents-suggest-spacex-may-launch-30000-more-starlink-satellites/)

3. Phy.Org: Astronomers say SpaceX's satellites are too bright in the sky. Friday's launch will try to fix that
https://phys.org/news/2020-01-astronomers-spacex-satellites-bright-sky.html (https://phys.org/news/2020-01-astronomers-spacex-satellites-bright-sky.html)

i knew I saw a problem when they said 'low cost design' and 'aerospace' in the same posting on their job website lol
Title: Re: Betelgeuse the star
Post by: RoGeorge on February 18, 2020, 08:20:25 am
Huge nice Orion pic:
(https://apod.nasa.gov/apod/image/2002/OrionOverCzech_Bauer_7954.jpg)

Same source:  Astronomy Picture of the Day.
Hover the mouse over the pic for annotations.
https://apod.nasa.gov/apod/astropix.html
Title: Re: Betelgeuse the star
Post by: BU508A on February 18, 2020, 11:56:07 am
The VLT in Chile has made some nice pictures as well:

(https://scx2.b-cdn.net/gfx/news/2020/esotelescope.jpg)

https://phys.org/news/2020-02-eso-telescope-surface-dim-betelgeuse.html (https://phys.org/news/2020-02-eso-telescope-surface-dim-betelgeuse.html)
Title: Re: Betelgeuse the star
Post by: BU508A on February 20, 2020, 12:30:46 pm
New findings about Betelgeuse:

(http://www.goominet.com/uploads/tx_cenostripviewer/wk324-betelgeuse.jpg)

Source:
http://www.goominet.com/unspeakable-vault/ (http://www.goominet.com/unspeakable-vault/)
Title: Re: Betelgeuse the star
Post by: Nominal Animal on February 20, 2020, 01:45:08 pm
My first thought was "It's winking", too.

As an aside, the two images of Betelgeuse are really good examples of an issue I've struggled with a lot: controlling the information content in a visualization image.

We do not actually know what the true resolution of the imaging machinery are with relation to the image dimensions.  The image we see could very well be reconstructed from data from as few as 25 separate imaging sensors ("pixels"), but smoothed out and "prettified" (filtered with a low-pass filter) so it doesn't just look like 25 squares of slightly different colors.  There is a huge risk of accidentally doing a computer-assisted Face on Mars (https://en.wikipedia.org/wiki/Face_on_Mars); but instead of light and shadow playing a trick on the viewer, the added interpolation/smoothing/filtering done to the digital data does it.

(In my case, the problem is that when visualizing molecules or atomic systems, displaying them as shiny spheres with perhaps sticks between them to illustrate bonds, gives completely wrong intuitive picture.  Atoms do not have clear boundaries at that scale, and when bonded, most definitely do not stay spherical.  So, using "less fidelity", or just non-photorealistic renderings like something from the graphics artists' toolbox, one can avoid causing such mis-conceptions and mis-intuitions by controlling the information conveyed [by adding non-realism!].  At the atomic level, especially when you have lattices (perhaps a metal), small clusters, and individual atoms, just defining exactly what constitutes a collision and how energy or momentum is exchanged, is hard.  They don't bounce off each other like people in a mosh pit, or pool balls, but tend to do pirouettes around each other like classical dancers.)
Title: Re: Betelgeuse the star
Post by: mcovington on February 20, 2020, 02:20:55 pm
I think it is rebrightening.  Data:
https://aavso.org/lcg/plot?auid=000-BBK-383&starname=BETELGEUSE&lastdays=60&start=&stop=2458898.53304&obscode=PTOB&obscode_symbol=2&obstotals=yes&calendar=calendar&forcetics=&pointsize=1&width=800&height=450&mag1=&mag2=&mean=&vmean=&grid=on&v=on
Title: Re: Betelgeuse the star
Post by: RoGeorge on March 06, 2020, 12:33:46 pm
https://www.youtube.com/watch?v=tpLCu145-Zk (https://www.youtube.com/watch?v=tpLCu145-Zk)
Title: Re: Betelgeuse the star
Post by: Gyro on March 06, 2020, 10:34:41 pm
Damn, I was hoping to live long enough to see the fireworks!  :(
Title: Re: Betelgeuse the star
Post by: mcovington on March 11, 2020, 01:14:33 am
Definitely rebrightening.  Graph (updated daily):
https://www.aavso.org/lcg/plot?auid=000-BBK-383&starname=BETELGEUSE&lastdays=60&start=&stop=&obscode=PTOB&obscode_symbol=2&obstotals=yes&calendar=calendar&forcetics=&pointsize=1&width=800&height=450&mag1=&mag2=&mean=&vmean=&grid=on&v=on (https://www.aavso.org/lcg/plot?auid=000-BBK-383&starname=BETELGEUSE&lastdays=60&start=&stop=&obscode=PTOB&obscode_symbol=2&obstotals=yes&calendar=calendar&forcetics=&pointsize=1&width=800&height=450&mag1=&mag2=&mean=&vmean=&grid=on&v=on)
Title: Re: Betelgeuse the star
Post by: Sal Ammoniac on March 11, 2020, 01:32:32 am
Yes, getting brighter. That's too bad--I was really hoping that she'd blow. That would have been a fantastic sight!
Title: Re: Betelgeuse the star
Post by: Gyro on June 16, 2021, 05:23:55 pm
Mystery solved, apparently it was a dust cloud...  :(

Quote
Astronomers say they've put to bed the mystery of why one of the most familiar stars in the night sky suddenly dimmed just over a year ago.

Betelgeuse, a red supergiant in the constellation of Orion, abruptly darkened in late 2019, early 2020.

The behaviour led many to speculate that it might be about to explode.

But a team using the Very Large Telescope (VLT) in Chile say the cause was almost certainly a giant dust cloud between us and the star.
...

https://www.bbc.co.uk/news/science-environment-57501416 (https://www.bbc.co.uk/news/science-environment-57501416)
Title: Re: Betelgeuse the star
Post by: coppercone2 on June 18, 2021, 03:03:26 am
how much of a electromagnetic disturbance would that star cause?

https://en.wikipedia.org/wiki/Near-Earth_supernova
Title: Re: Betelgeuse the star
Post by: jmelson on June 18, 2021, 04:04:51 pm
how much of a electromagnetic disturbance would that star cause?
Not much.  It is about 500-600 light years away, and its axis is not pointed at us.  it would be bright for months, for sure, and might be detectable by some instruments other than optical telescopes.

Jon