Hello, I have a few questions about black holes
Me and a friend of mine, are working on a presentation about black holes.
We've thought of a few good questions we wanted to answer in our presenattion.
Most of them we could answer ourselves, but we're struggeling on anwsering the question:
What are the requirements for a star to become a black hole?
OP here, about the question, more detailed question: Why dont the stars become white dwarfs or neutronstars?
From what I've read, it needs to be a star several magnitudes larger than our sun with a massive amount of Iron at its core. This contributes to a point of density and describes an incredibly high pressure core during the super nova that can collapse into a black hole.
Our sin cant do this and in a few billion years, will die a white dwarf.
>>7778769
White dwarfs do become neutron stars, which are stabilised against further collapse by degeneracy pressure. However a white dwarf 3 times heavier than the sun will always collapse into a black hole (cf. Tolman–Oppenheimer–Volkoff limit).
>>7778783
So the iron basically makes the star a lot heavier than stars that dont, does this also affect the speed of the collaps?
>>7778790
Because thats not a dwarf. Or is our sun a dwarf star?
>>7778794
Iron is a star killer simply because it kills nucleosynthesis at the core of the star.
Iron (specifically Iron - 56) consumes more energy, and at the moment of its introduction at the heart of the star fusion cannot withstand the enormous force of gravity, and the star collapses.
>>7778794
It doesn't make it "heavier," it makes the core denser. So the core holds form under the extreme pressure of the super nova and eventually collapses in on its self.
OP here again, thanks a lot for the help so far,
however i'm very needy and have more questions.
Can someone explain the no hair theorem?
I want to point out, i haven't had any education in this subject and am just a High school student, so i apologize for my ignorance.
>>7778769
In simple terms, the collapse of the star has to be violent enough to push past the point of being a neutron star. This can only happen if the star in question is extremely massive.
>>7778823
No, iron is the element that forces the star to collapse. Whether or not a black hole forms greatly depends on the mass of the core exceeding what is called the "Chandrasekhar Limit". But I digress.
>>7778827
Oh thanks, I'll look into the "Chandrasekhar Limit" then.
>>7778823
It doesnt hold it together, it provides an area within the star that wont disintegrate or blow away with the rest of the material. The iron can also absorb a lot of energy, its why the star dies in the first place. So an incredible amount of energy is required to collapse the entire star into a black hole. That means the star has to be huge.
>>7778836
You bet.
It would also be advisable to look into how core collapse supernovas form, and the various different types of novas and supernovas.
Also, look into the topic of Main Sequence Stars....notably how they are formed, and why our own Sun will never become a black hole when it perishes :)
>>7778803
What? A white dwarf is the end point of stellar evolution for main sequence stars from a certain mass range that I don't remember. Our sun is in that mass range so will eventually end up as a white dwarf. However after that if the white dwarf is still more than 1.5 the Mass of the sun then electron degeneracy pressure can stabilise it against further collapse, this is the Chandrasekhar limit. After that if its only slightly more massive then it will collapse further into a neutron star, which again is stabilised by degeneracy pressure (this time neutron degeneracy), eventually its core will become more massive than the mass that degeneracy pressure can stabilise against and so collapses, this becomes a becomes a black hole.
>>7778854
thanks a lot man
>>7778878
No sweat. Good luck anon
>>7778855
>This
>>7778763
They just made a telescope to take the first photo of a actual black hole, add that
My life
You electrify my life
Let's conspire to ignite
All the souls that would die just to feel alive
I'll never let you go
If you promise not to fade away
Never fade away
Our hopes and expectations
Black holes and revelations
Our hopes and expectations
Black holes and revelations
>>7779001
>Listening to Muse
I've found the faggot.
>>7778897
>They just made a telescope
No, they didn't, they will use current radiotelescopes all around the world to detect radio waves from a black hole sagittarius A* witch is in the center of our galaxy.
