Evolution of High Mass Stars
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- Опубликовано: 25 июл 2024
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High-mass stars are the flashy parts of Stellar Evolution. We see the speedy and violent stellar nucleosynthesis that occurs inside their cores. These extremely rare supergiant stars live short lives and make a lot of stuff. High-mass stars evolve much more rapidly, and their endings are extraordinary. They are responsible for many of the elements that make up your body! This is part of my complete intro Astronomy class that I taught at Willam Paterson University and CUNY Hunter.
Stellar Evolution: en.wikipedia.org/wiki/Stellar...
Stellar nucleosynthesis: en.wikipedia.org/wiki/Stellar...
Nucleosynthesis: en.wikipedia.org/wiki/Nucleos...
Supergiant star: en.wikipedia.org/wiki/Supergi...
Planetary Nebula: en.wikipedia.org/wiki/Planeta...
Nuclear binding energy: en.wikipedia.org/wiki/Nuclear...
Iron Peak: en.wikipedia.org/wiki/Iron_peak
0:00 Introduction
0:33 All stars are born, live and die
1:28 Life Cycles of Stars
2:54 Red Giants in the Sky
6:37 Betelgeuse is a Rare Star
7:30 Betelgeuse's Vital Stats
9:35 Betelgeuse's Portrait
14:47 The Sizes of Stars
15:27 The Proton-Proton Chain?
15:58 CNO Cycle is for Massive, Hotter stars...
19:47 No Party Lasts Forever...
22:47 No Helium Flash Photography Please
23:25 Blue Supergiant
25:00 Helium Core Exhaustion
27:23 Carbon Burning
29:58 Intermediate Mass Stars
31:21 High Mass Stars: Greater than 8 times Mo
32:42 Neon Burning
34:52 Oxygen Burning
36:31 Silicon Burning
39:12 The Iron Peak
40:47 The Ends of the Roads 
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I've corrected a couple mistakes and fixed some serious audio issues.
Please see the updated version here: ruclips.net/p/PLyu4Fovbph6d9PJ25kXjmEDSAXQp76Mpl
Your stuff really is quite comprehensive and straightforward. That is not easy to find. Thank you.
Thanks!
It is hard to find.
Informative, well delivered and NO EXAM IN THE MORNING. Thank You.
Our pleasure!
I was watching space videos for long time, I learned a ton, so your videos are at the right level for me now.
I love your lectures going just somewhat deeper in the matter, without getting too tecdhnical for me to follow. Hope for clear skies when I visit my mother wehere the is less light pollution than over here in the west of the netherlands.
Your videos are great! Here, I've learned a lot about the lifecycles of the giants in our stellar neighborhood
I actually like the stellar evolution set. I can never do it for a public talk, but I like the narrative...
Whoa, in depth lectures? (Astrogasm) this channel needs to be bigger.
You deserve way more subscribers and views than you have. Thank you so much for sharing your knowledge about the subject.
So nice of you
Once again, you have done a stellar job of explaning the intricacies of astronomy and astrophysics. Thank you.
Fascinating. Exceptionally well presented for the average layman like myself adding significantly to my understanding on the subject. I always look at Betelgeuse at night.
Amazing video. Thank you much. Better than my univ level professor!
thanks for these videos. Learned all this stuff in college but i mostly forgot it. This is great review
Very Interesting Media.
THANKS
Very informative thank you
Excellent video my dude, really enjoyed this
Love this
Curiously the total mass of each category is roughly the same until the very largest stars. Perhaps because most modest mass stars are still extant while most high mass stars are already defunct.
Eta Carina explosion with duel bubbles is how I imaged, as child of 8, the big bang explosion happened with a positive good universe and a negative bad universe that was supported by an Star Trek episode What of Lazarus, where good Lazarus was dedicated to keeping the negative Lazarus out of our positive universe by locking himself in a membrane between the two universes... then I became aware of the inflation model so remodeled my vision of the starting event which physicist said was neither big nor made a bang.
Since you start with a few solar masses of protons, and turn half of them into neutrons, you need to get rid of more than 10^(33+23) electrons, or else you’ll have too much charge. Fusion positrons will do that. But you also need to shed lepton number ( it’s conserved): enter….or exit really… the neutrino.
For every proton that becomes a neutron, a neutrino has to leave the star.
Why don't Ni(p,γ)Cu or Ni(α,γ)Zn processes happen in heavy stars during Si burn but before core collapse begins? Assume stellar core has grav-energy to spend.
I just hope that Betelgeuse doesn't go supernova in my lifetime. I like her where she is.
Why don't heavy stars fuze iron even at the net energy loss? Why heavy stars don't overshoot the iron peak? Iron cores have enough gravitational energy to spend on iron fusion but they don't.
Why have you removed the convenient numbering scheme? I found that very helpful, now I’m not sure where I was...
You can go to my website to see the ordering. Or watch them using the playlist. Either way will get you the ordering.
to lift 64,000 tons up a kilometer seems outrageous from 1 gram of matter. In chemistry I saw what 1 gram was, one cubic centimeter of water. But the numbers of the cno cycle in density are so out of normal we just have trouble susing exactly what that means. That is why I am so much a proponent of molten salt thorium reactors, to replace our oil dependency now. Now that Goodenough and Bragga have discovered a million mile lithium battery in solid state glass that will not burn down and degrade over time like lithium ion electrolyte batteries, "hey we can do this". For the next thousand years at least.
got a link to that solid state battery?
Ah Betelgeuse I find it interesting that the only reason it is so prominently visible is due to it having been launched out of the Orion Nebula at high velocity probably due to gravitational interactions when it was a newborn star otherwise it would be hidden away behind all the gas and dust like its siblings in the Orion Nebula.
Eta Carinae is a interesting system of uncertain stage one of those extremely rare behemoths with over a hundred solar masses even its smaller companion is at least 30 solar masses in other words crazy massive stars.
Personally the weirdest and perhaps most fascinating stars are the monstrous WNh stars since their CNO cycle burning and rapid rotations drive internal convection rapidly burning through their entire envelope of hydrogen and beyond losing nearly all their angular momentum to extreme outflows. Depending on circumstances they might not even produce Supernovae instead dying with a whimper by collapsing straight into a black hole without a gamma ray burst since they have no angular momentum left to lose though that remains speculative since these stars are too rare. Weirdly enough WNh stars are still fusing hydrogen in their cores because of this effectively never existing as a typical main sequence spectral type. I think its thought these develop straight into Luminous Blue Variables which in turn evolve into more conventional Wolf Raynet Stars. Have you done any video on the Wolf Raynet class? The stars covered here are the less massive "low mass" supernovae progenitors alternating between the red and blue super giant phases with the transitional yellow hyper giant phase. And then there are those population III stars from the Early universe which are though to be able to die via pair instability supernovae as the photo disintegration is able to dominate. Massive stars are complicated....
dragrath: hmmm did you know sn 1987a was not a rayet star. seems it was just a blue giant. I would dearly love for our stellar astro-phycists to explain exactly simply to me how the rings were formed as it dynamited into a supernova. And what the glint was that was spotted some close distance away by the Harvard-Smithsonian telescope shortly after the burst, that then went quickly away. Something happened during detonation that was almost superluminal and I am not sure if it was a relativity space/time view from our angle or was really super-luminal in nature.
@@PaulHigginbothamSr you know, look up few papers on it. If you find something close to what you need. Write the author. The PI's and grad students are usually pretty responsive.
I’m confused. At 38:48 he mentions that the atomic number of Iron is 56. I thought the atomic number of Iron is 26, with its mass being ~56. Am I misunderstanding something?
No you got it right. I mis-spoke and I try to do these in one shot. I guess I need to do shorter videos and script it out....
Jason Kendall
Thank you for the clarification Jason. And most importantly, thank you for these awesome videos!
that's probably what he meant; ive noticed a few minor errors here and there. if only youtube let you edit videos... annotations could work, if someone were to put in the time...
I know. I wish I could. I try to do them in one sitting, with zero edits. As though I'm giving an actual lecture. I do have a few flubs, so I do appreciate the patience.
WARNING!! Ear destruction at 3:29
I do need to do some work on it...
Aren't the really heavy metals like gold and platinum only created by neutron stars colliding?
That's correct. I think I put that as an errata/correction on the video. If not, then here it is...
Awesome stuff, but also the second lecture with a horrible noise that scared the crap out of me. Your audio is pretty low so I had to crank it up pretty high and at 3:30 mark I almost died
Yeah this is one of main reasons I’m redoing the whole series.
Thanks for the timing note.
What if you’re single?!? Where’s my gold?
In your teeth 😁
Buried in your backyard most likely.