Type II Supernova - Sixty Symbols
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- Опубликовано: 12 сен 2024
- After last week's excitement (see our astronomy sister channel at / deepskyvideos for more details), we turn our attention to types of supernova.
Featuring Professor Mike Merrifield.
Deep Sky Videos on last week's Type II can be found at:
• Supernova in M95 (NEWS...
• The star that blew up ...
As usual, here is Mike explaining the Atlas of Creation on his shelf: • Atlas of Creation
Visit our website at www.sixtysymbol...
We're on Facebook at / sixtysymbols
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This project features scientists from The University of Nottingham
Sixty Symbols videos by Brady Haran
Catches the ball while continuing to describe the process like a boss.
I have goosebumps whenever a Sixtysymbol / Deepsky / Nottinghamscience video is out. I just know its high-quality, super awesome video.
"Flung Far Further than it Fell From in the First place" 3, 2, 1 Fs, that's some Numberphile sequence right there
Thanks for doing all this.
B B64 your welcome
np
There are some heavy elements that can ONLY be created in a supernova like Uranium. I think the heaviest element that can be created in a main sequence star is Iron. Once its burning iron the end comes very quickly. I'm not an astrophysicist but I believe main sequence is H > He > C > O > Fe.
see our video about it on nottinghamscience... link in the vid description
Brady, you should make a compilation video of how many times someone has said to you "that's a good question". lol...I think that's a hell of a compliment coming from professors and scientists.
see video link about this in the full vid description
Nice explanation of the "bounce" for collapse to explosion. Cheers for that.
So very cute so to see a physicist play - that expression at 5:21 makes me all warm inside. Such innocent, childish joy.
I'm really surprised those videos have so little views. I really enjoy watching this channel's content.
Great video, to add to the story...
If you were able to get little fingers on the strings under the keyboard of an upright piano when you were young, then you could watch the vibration shift from one set of strings to another after a note was struck and the instrument as a whole was left to resonate into silence. It looked strange to see the vibration move about without the strings touching. Then the story of waves and synchronizing clocks on a shelf was told about a repair shop for clocks.
The bending of space by gravity changes the resonant frequency of the space included in the squeeze and forces longer wavelengths out. Once the process is underway the "resting" phase of neutrinos can be conducted anywhere in the system.
Nova are a very dramatic version of frequency shifting and Black Holes intriguing, but still the same mechanism. (superficially, modulation - demodulation)
This was seen eight years ago. At first I thought I could go out and see it but I was eight years late.
I am amazed that simple illustration like that can convey such an interesting concept effortlessly!
Mrleonard I agree with most of what you're saying here. We call it 'white' because it's all colors combined. There is no actual 'white' color. White is how we perceive all colors at the same time. As I said in an earlier post only a laser would have a single bandwidth of light. And I agree it's hard to argue the color of white when what 'white' is depends on what you calibrate it to be. It changes based on what you're comparing it to.
The point I was making is that we have little to fear from supernova stars because the energy is delivered in all directions at once meaning very little of it eventually makes its way in our direction. And objects that deliver energy with tight focus are so far away and unlikely that we would be inside of the limited area they eject particles that we also have little to worry about.
thanks... hope this one was good enough! ;)
You guys make my day whenever I come back from university and there's a video from you.
Brady could you guys do a video about wind power?
A black hole will devour anything that crosses it's event horizon. But as it devours it, the matter heats up as it's ripped apart and this releases energy in the form of x-rays. A convenient way to detect a feeding black hole is to look for these x-rays. However this radiation pushes back on anything coming close to the black hole. The more it feeds the stronger this push, until nothing can get close enough to cross the event horizon, and it goes dormant.
3:57 = badass catch!
3:59 telekinesis powers.
"flung far further than it fell from in the first place." nice alliteration!
I don't think anyone who gets first actually waits to watch the video before they comment. :)
IIRC, what's actually happening is that the Hydrogen that's left in the shell that gets exploded out is what's causing the absorption. The Hydrogen in the very center (core) of the star has indeed been exhausted and started to fuse into heavier elements before it gets to Iron, which can't be fused further and halts the nuclear fusion.
I find it amazing that the explosions are so incredibly bright even though they're so far away.
The reason why is because it's so large it actually makes measuring it difficult. To guess it's distance you have to guess it's mass, it's circumference, and it's brightness. If any of these numbers are off then your distance is off. There are few local stars as large for us to fine tune our equations on so we make an educated guess with a stated error factor.
When things get hot they give out light e.g. an electric hob glows red, a lightbulb glows yellow. The hotter you make something the bluer/whiter it glows. The technical term is Black-body Radiation.
@MrLeonardfalkland, @Subparanon
It's not only a matter of calibration and semantics. Yes, some people may perceive it as yellowish, some as white with blueish tinge. But for average person it will appear as truly white. That's why I used the term "by average human eye". I'm talking about sunlight beyond atmosphere. This whole color perception thing is described by colorimetry.
That was a pretty badass catch on that first drop there. Does Prof. Merrifield play any sports?
I've just completed an EPQ in neutron stars, pulsars and the Chandrasekhar Limit, really interesting :D I do love cosmology and astrophysics
I imagine it would be very easy, as supernovae are many times brighter than a star forming, but the moment of a star's ignition (so to speak) is I imagine brighter than a star just sitting there being stellar.
continued from above. So it's wrong to say that we perceive the sun to be yellow because of atmospheric scattering. We know the color of true sunlight, as measured from space, and we can reproduce that color here on earth with simple photographic equipment or a calibrated computer monitor. Regardless of whether it's overhead, or staring you right in the face, the 'white' sunlight has a yellowish tinge. When compared to D65 which is the universal white, sunlight is obviously yellow.
I'm not a astrophysicist but it strikes me that the answer could be quite simple. If you examine the space between the two stars there is a point where the gravitational forces of the bodies are equal, while matter on either side will fall to one star or the other. If a white dwarf is close enough to the larger companion star it might be that gas on the outer edge of the larger star finds it self on the white dwarf side of that point. As a result it would get pulled away into the dwarf.
It's a yellow star by definition. But it also emits full spectra. So, in space it would appear white because of the saturation on rgb receptors in the eye. But you're right in spectrometer it would show peaks around 590nm witch is yellow. Thanks for reply
I've never been to Egypt either but I know what the pyramids at Giza look like. The wonderful thing about technology is that people can take pictures of places they've been and the rest of us can see them. We also have satellites dedicated to studying our sun and if you've ever seen the images they send back, you will not see a white star but a yellow/orange one.
That is a fission reaction where two sub critical masses of plutonium are suddenly brought in close proximity or a sphere is crushed to a critical mass and it explodes. The sun works on fusion reactions and it's already under thousands of times more pressure than any explosion can crush plutonium in a warhead. It's not the collapse that makes the plutonium go critical it's the proximity. But you need it to explode on command so they keep the mass sub critical until go time.
I mention albedo because it's a measurement of the reflectivity of an object. If you have a black object and a white one in the same light, the white is brighter. For instance comets tend to have a greater albedo or reflectivity than asteroids therefor they appear brighter given similar distances and sizes. From an albedo standpoint I think Enceladus is the brightest object in our solar system.
Good catch.
To put it simply a black hole eats in moderation. Once dormant it lies in wait for some orbiting body to get close enough to begin feeding again and the cycle repeats. Thats why the supermassive black holes at the center of galaxies aren't in any danger of consuming the entire galaxy, just the closest stars in the center. The energy released from eating a galaxy would ironically prevent it from eating that galaxy.
that catch was so cool
@MrLeonardfalkland, @Subparanon
PS. I perceive sunlight as virtually white, at noon the sunny day.
PS2. I perceive the color of clouds (which scatter all wavelengths approximately equally) on sunny days as white.
PS3. I perceive bulb light as yellowish.
PS4. The peak of emission of the Sun would lie at 500 nm if it radiated like an ideal black body. In practice however, there are some small deviations that shift it to the shorter wavelengths.
They will indeed become neutron stars. A neutron star forms when the remnant exceeds the Chandrasekhar limit (the maximum mass of a white dwarf), which is 1.38 solar masses. When the remnant exceeds the Tolman-Oppenheimer-Volkoff limit (the maximum mass of a neutron star), which is about 3 solar masses, then it becomes a black hole.
There are different temperatures of white light that give different tints. The calibrated standard for sunlight is 6500 degrees kelvin. 9000 kelvin would be bluish white and 5000 would be redder. I don't know if it's the same temperature that gave the light off or if it's a different kelvin measurement strictly for color reproduction. Anyway in answer to your question sunlight is about 6500 kelvin.
Being an undergraduate it should be simple for you to understand that there is no such color as white. And when I say the sun is yellow. I'm talking only about it's spectrum classification type GV2, yellow star. And when I say sunlight looks yellowish, I'm referring to the color temperature as referenced against pure white D65. Not the light as it comes through our atmosphere, but it's actual color temperature in kelvin. Sincerely guy tired of replying to a settled issue.
@puncheex and @Subparanon Thanks you for explaining this, I appreciate it.
One correction type Ia supernovae are the exploding white dwarfs. There are two more types of SNe I which are type Ib and type Ic which also core collapse supernovae, like type IIs, but of more massive stars that have expelled their Hydrogen (Ib) and Helium shells (Ic), so they don't show any Hydrogen in their spectra, hence their typing as SN I and not SN II.
[My apologies if someone has already raised this -- there are more than 300 prior comments, and that's more than I can handle at the moment.] Possible (albeit slightly farfetched) "weight loss" scenario: what if a star that's initially above the 8-solar-mass limit becomes a close binry system with a white dwarf (this requires a mechanism that allows such a pairing to take place, as it is entirely clear that the two cannot have formed together), after which it loses enough mass that it goes below the limit? (I'm guessing that this is likely to push the white dwarf into becoming a supernova, but that's a partially separate issue.)
If assuming gamma rays travel at the speed of light and if the estimates are correct that we are about 350 to 600 light years away then there you have it. They said it has been very hard to calculate the exact distance of Betelgeuse from Earth.
BRADDYY!!!
can you ask these guys and girls what colour our sun is b/c I've gotten into a little bit of a fight with my friend about what colour it actually is.
if not then thats cool too.
I didn't realize he had a corner office. Nice. Nice aliteration, too.
Good work guys.
When the supernova went off is roughly how far away the galaxy is. Someone in M31 could observe a supernova in our galaxy, but, depending on where the supernova went off, their distance estimate could be off by 100,000 lightyears.
Nice catch at 3:57.
Our sun is spectra class GV2, that makes it a yellow star. We are arguing semantics. Sunlight contains all colors so we call it white. But the proportions of these colors aren't the same. So we need a way to differentiate different tints of white light. We use the kelvin measurement. 'White' can be whatever you calibrate it to be. In the calibration for star spectroscopy, our sun is YELLOW. Compared to D65 it's subtle peach. Compared to Aldeberan it's blueish. So you are arguing perception.
Cheers for the unbelievably fast response .
Heat is what we call it when electrons get excited. Sometimes an excited electron gets kicked up a notch but it's not stable and it wants to be stable, so that excess energy is given off as a photon and then it returns to it's original shell. The hotter it is, the more electrons get kicked up and give off a photon before falling back and the more photons there are. I don't know what about black body radiation causes photons to have a specific wavelength of light.
"... getting Flung Far Further than it Fell From in the First place..."
He should have said that with his best Daffy Duck voice.
What an event that would be. Watching a supernova with your naked eye at 12 pm.
It would be pretty damn cool if that nearby star went supernova in our lifetime. Kinda scary too, maybe. x) But really cool!
Nice catch!
You're talking about how you perceive color. I'm talking about what color it actually is. Our sun is a GV2, this is a yellow star. This fact cannot be disputed. Regardless of how different all of our eyes and color perception are, the sun is a yellow star.
so keeping with the tennis ball and football analogy, does the football represent the portion of matter that will collapse into a neutron star, and the tennis ball represent the matter flung out into space by the rebound? And if so, would the heavy elements created during a super nova be fused into being from the rebound energy around the point of contact between the two?
"It's not quite understood how something that collapses can create that big of an explosion." Yeah okay, but how about a Plutonium powered nuclear bom? It's based onto collapse of the Plutonium pit and the results are very clear. And very bright.
That is a good question. Nobody knows the answer. Right now the universe is expanding faster and faster with no signs it will slow or collapse back on itself. If the universe expands forever then no, everything will be too far apart for even the gravity of a black hole to bring it close enough to devour. Nobody knows if a singularity can go supernova, but black holes do lose matter over time almost like evaporation. Due to subatomic physics properties. Ive often wondered your question myself.
Sixtysymbols, so the reason one type of supernova has hydrogen absorption lines and the other doesn't is because one type is caused by a star that's already fused all it's hydrogen and the other type from a star that hasn't right? If a star fused all it's hydrogen to helium to carbon to oxygen to iron then there wouldn't be any hydrogen signature in the spectrum right?
Light's apparent brightness drops by the square of it's distance from you. Move twice as far from a light and it's 4 times dimmer. Look at the night sky right now and you will see Venus and Jupiter very close to each other. Jupiter is many times the mass and size of Venus and not getting into details like albedo, lets say they have similar reflectivity. One is significantly brighter than the other and it's Venus. It appears brighter because it's much closer. Light falls off by the square of dist
Thank you for the response. answered my question exactly.
Great video!
You guys are having WAY too much fun with dropping the balls in the office. :-)
I understand that there are laboratories that have neutrino detectors for the sun, but what about other stars? With the understanding that neutrino-fermion interactions are extremely rare (relatively speaking), how large of a structure would be required to not only detect neutrino-fermion interactions, but to also determine the origin of a neutrino to within 100 arcseconds?
I have to ask is there an example of a classification being pronounced redundant?
Particularly because of better understanding of the phenomenon classified
The closest thing I can think of is star classifications
Second correction. Type Ia supernova do not really reach the Chandrasekhar mass and collapse. When they get close to it the conditions inside the white dwarf get to the point where it can re-ignite Carbon burning. Because the Carbon is in a degenerate state that burning is a violent runaway process which extracts so much energy it is more then the WD binding energy, leading to t's total destruction. BTW, this is another major difference, type II, Ib, and Ic leave a remnant while type Ia do not.
That makes sense but the apparent color of the sun doesn't change significantly without an atmosphere. On the moon for instance sunlight is still yellow orange compared to pure white.
i really hope i get to see a supernova or something else besides a moon and sun in the sky within my lifetime
+The Collector I was already fascinated by seeing the Moon, Venus, and Jupiter really close to eachother in the sky in the first half of the year. A supernova in the sky would be absolutely amazing!
If the wandering black holes manage to suck up all or most of the matter in the universe and drift really far apart due to the expansion of the universe then it could stand to reason that our known universe is actually only one of many that were formed by multiple big bangs from a previous universe going through the same process. This could be a different multivers theory, though I think a superverse would be a more appropriate name for the former universe that these others exploded into.
Yellow is just a mixture of light to dude. It's not like the sun is only sending yellow light our way. But the mixture of different wavelengths comes out as yellow. If the sun were hotter these wavelengths would be in different proportions and the color would change. Even colored light has multiple wavelengths unless we're talking about a laser. It's disingenuous to say that sunlight is white.
Thanks for the clarification. But isn't it correct that this is the part where we get the heavier elements?
Sixtysymbols, since even wikipedia lacks references to any statements about the color of the sun, perhaps some actual physicists could chime in and settle this little debate about the true color of our sun and how we perceive different temperatures of white light.
It takes about 640 years for the light to reach our planet. Gravity waves also travel at the speed of light, so if it were to go supernova, neither it, nor any stars around it would show any effect for hundreds of years back on Earth. If our own sun were to blow up, we wouldn't know about it for the better part of 10 minutes. If our sun disappeared the earth would keep right on orbiting for those 8 1/2 minutes because it takes that long for the gravity wave to reach us as well.
Nuclear fusion is a very efficient process. The Sun looses just a tiny fraction of its mass (about 4 million tons, which means less than 1 trillionth of total). This happens during hundreds of million years, perhaps billion years.
At the moment of the supernova event, all the mass falls down to the center and bounces at the nucleous just in few seconds, which generates a powerful shockwave, that could spreads 90% of the total mass. This dramatic explosion is responsible for so much bright light.
If you saw it at night, it would be brighter than the Moon. "Spectacular" doesn't even begin to describe it. So let's all hope that it actually exploded hundreds of years ago and the light from the supernova is almost here :-)
And our atmosphere is not 'air tight' as the expression goes. We do lose atmosphere to space every day. Helium for instance is so light that not even earths gravity can bind it and it eventually gets out into space. Most of the helium on earth comes from natural gas deposits. If it were in our atmosphere only it would have been gone long ago. The only reason it's in natural gas is because it's a decay product of radioactive elements so we have a source that is slowly refreshed until rad mat deca
Well again, nobody can say for sure that our big bang was the only one. But we don't have enough information to even begin guessing if there are other universes or what they might be like or even how the physics of that would work out. Black holes will not devour everything in the universe though. Gravity is a very weak force. Two objects need to be close together in order to be pulled in towards each other. This will take a few replies to fit it all.
They are all professors at the University of Nottingham or Grad students, hence their ability to explain the complexities of their respective fields.
I DIDNT EVEN KNOW DEEPSKY WAS A CHANNEL.
@ninjaplease123 because sunlight reflects off of them, just like the moon or Earth in sunlight
Wrap your minds around this boys and girls. The light you are seeing from our own sun might have only taken 8 1/2 minutes to reach your eyes but it took much longer than that to reach the surface of the sun and be radiated in our direction. The sun is so dense it can take ages for a photon to work it's way through all of that matter to be radiated as light. Look it up and be fascinated. Those photons you see as sunlight might be older than our species.
Brady could you ask the Professor if a star can just completely burn out and cease to exist, or do stars always end their lives very violently?
Exactly, they are some of the farthest objects to be seen. I'm talking about the feeding cycle of a supermassive black hole which so far as we know exist only in the center of galaxies. They beam intense radiation out of the top and bottom when on a feeding cycle and if a galaxy were 'aimed' at us and nearbye it could be problematic but there are no such galaxies that we know of.
Actually no they do not have infinite density. If they did they would contain infinite mass and they don't. They contain a finite amount of mass, compressed into a very small amount of space, which is it'self not infinitely small. It's smaller than we can measure so far but not infinitely so.
I've often wondered if our universe went to infinity in all directions or if it were a multi dimensional plane like a mobius strip that curved back around until it ended up back where it began. If you think of our 4 dimensions as a piece of paper, perhaps in the fifth dimension that paper would form a sphere and our universe is expanding on one side of the sphere like ripples on the surface of a bubble and eventually they will meet on the far side. Nobody knows.
I'd be interested in learning more about black holes. Is the ultimate fate of the universe of all mater to be trapped inside these wandering singularities that may eventually consume one another?
Would it be possible for the density of a black hole to reach a point where it can no longer hold the matter within it, resulting in an explosion? Perhaps this is the origin of the big bang?
It can't be 0 K, but it can get really close. Also, black holes can be considered completely black as they don't reflect light.
wow he explained it VERY well.. easy to comprehend.. just subbed and I saw this from vsauce :3
Since we are made of supernova ejecta, is there a neutron star out there we can point to as the probable star that had provided the raw material for our solar system?
Professor Mike Merrifield,
When you see that there's a process in which stars may lose mass before the end of their life are you referring to the Wolf-Reyet star? We actually observed a wolf-Reyet star exploding in a supernova I am not very knowledgeable on the supernova itself or processes in which a start may lose energy and lose mass yet still explode in a supernova. But is it possible that a normal or giant star they undergo the same processes?
Why need neutrinos to explain the energy source for flinging out matter?
Once H and He fusion stop and the core collapses, wouldn't the pressure cause the next higher elements to fuse thus releasing their own energy in the reactions?
That is how the rest of the natural elements on the periodic table came about I believe, but that fusion has nowhere near enough energy to cause a supernova. After Iron, fusion cannot release enough energy to keep the star alive, so there is no way that fusion would be able to give more energy to cause supernovae, as far as I know.
To be precise, the core material of the collapsing star is never going to be released into space.
What happens is, the different outer layers of the star slam into the core and richochet back up, similar to the Tennis ball in this video.
On their way up, they collide with other layers that are still on their way down. In that collision all the elements of the periodic table are formed (besides Hydrogen and Helium, of course) and flung into space, where they eventually hit and enrich primordial hydrogen clouds and cause them to collapse into new stars and planets.
I guess the combination of the universes expansion, and our own galaxies movement through it, must add up to almost light speed, or it wouldn't of taken 95% percent or so of the universes life span for this light to reach us?
there is actually a video on that. why he has that book on his shelf
Can you make a video about the Imaginary Time theory?. I read about it recently but i dont think the book gives a good enough explanation of it.