if it is a star is 2.8 times bigger than the sun it would become a neutron star just 20 kilometers across. (to put that into perspective, if a star where 2.8 times bigger than our sun and it became a neutron star it would be about the size of a small city!) the neutron soup inside keeps it from collapsing any farther. but what if it's MORE than 2.8 times bigger than the sun???
when the star collapses that is more than 2.8 times bigger than the sun, it collapses even farther. when that happens nothing in the entire UNIVERSE CAN STOP IT, NOTHING! than it will become infinitely dense and its gravity will be so intense not even light can escape its event horizon! (so basically what happens in a black hole, stays in a black hole)
and so a black hole is formed
if you have any questions i'll be happy to answer them (-:
: picy
Im sure VY canis majoris will
@Sunnyskies yeah i'll have to watch that some time soon, thanks (-:
@picy PBS Space Time has a very informative video on it.
@Flightsonic i dunno, just haven't heard of that
@Sunnyskies huh, i heard that on "crash coarse astronomy"
@picy Read up on it while ago, why?
@Flightsonic were did you hear that?
@picy Basically, any element lighter than Iron produces an exothermic fusion reaction, which releases energy. Anything heavier is endothermic, meaning fusion would absorb energy. The release of energy by the fusion process is the primary force keeping the core in equilibrium with its own gravitation. Run out of exothermic fusion fuel, and BAM! Gravity wins.
Another way for a black hole to form:
A neutron star is like a black hole, but not small enough (Sorta, there's more to it)
When a star collapses into a neutron star, the gravity is so intense that electrons will bind with protons, creating neutrons. And since neutrons don't have an electric charge, they clump up into the most dense object that quantum physics allows (It says that 2 particles can't be in the same place at the same time, which goes to their potential quantum momentum)
As a neutron star collects matter from another star (seen in binary star systems) it gets smaller, until its potential event horizon is larger than the star, when a singularity is created and it becomes a black hole
@Sunnyskies yeah i had heard of the fusion of elements down to iron but i didn't know exactly how it worked, so just left it out /-:
@picy You're on the right track. Particularly about stellar masses. Core collapse is an amazing process. Lots of fun things go on to make the magic happen. Astrophysics is one of my favorite fields (right up there with aviation and aeronautics).
@Sunnyskies uuuuuuuuu... yeah I'm way out of my league here
(but hey i'm 14 so i kinda expected to miss some stuff )-: )
It's only the core that collapses, not the entire star. The outward pressure of energy being released by fusion in a star's core resists the colossal inward pressure of the gravity generated by the star's immense mass. As the core runs out of fusible hydrogen, it goes through its helium, carbon, neon, oxygen, and silicon (silicon lasting only days before exhaustion. Once the core is left with only the nickel and iron products, the fun begins. You see, iron cannot produce energy through fusion, so the stellar engine breaks down. No more energy is being radiated outward, so gravity begins to take over. Then, it's up to the Pauli exclusion principle, the degeneracy pressure of electrons. Once the hard Chandrasekhar limit is passed by the core under this pressure, exclusion breaks down, and all the matter is pushed inward at a quarter the speed of light! Protons and electrons are merged into neutrinos which escape the core, and all that is left behind is a degenerate mass of quantum compacted neutrons. This is such an energetic event, it creates a rebounded shock wave so powerful, it shreds apart all the outer layers of the star, blasting matter outward to form a stellar nebula. Now a collapse into a black hole is something entirely weirdly different. Thanks to quantum behavior of the material the neutron star is made of, the size of a neutron star remains constant as its mass is changed. This means if a neutron star is massive enough, its Schwarzschild radius will rest outside its limb, creating an event horizon, and causing a black hole to form. This also means that if a neutron star's Schwarzschild radius is still within its limb, it can be coaxed outward by adding mass to it until the event horizon forms, since a neutron star's volume will remain constant. Physics as we know it breaks down behind the horizon, so we have no way of knowing for exactly what occurs beneath it. All we know is that the gravity is so strong, it has command over light, and stops time itself. Scary stuff.
here's a video that i think explains it pretty well
https://www.youtube.com/watch?v=3pAnRKD4raY
@picy Well that's true if you don't factor general relativity
@Flightsonic well the escape velocity is equal to the speed of light. meaning that if light goes into the black hole it cannot escape it's gravitational pull.
so its not that its frozen in time, it's that it is literally impossible for light to escape it
It's not only that light can't escape that makes it so dark, the time dilation is so extreme that the light would be frozen in time, and objects near the event horizon would be redshifted so extremely that they're undetectable
if i spelled anything wrong or you don't understand something
just leave it comments
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