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Black Hole Stars
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black hole Stars may have been the largest stars that ever existed they burned brighter than galaxies and were larger than any Star today or that could ever exist in the future but besides their scale what makes them special and weird is that deep in sight they were occupied by a cosmic parasite an endlessly hungry black hole how is that even possible [Music]
0:33
black hole Stars take the weirdness of black holes and go beyond to break everything we know about how stars form and grow they were only possible during a short window of time in the early universe but if they existed they would solve one of the largest mysteries of cosmology black hole stars were excessive anywh you look at them the most massive stars today may have about 300 solar masses a black full Star had up to 10 million solar masses of nearly pure hydrogen let's take a moment to look at
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what this means visually the sun weson LL pegasi the largest star and finally the black hole star its scale is beyond words over 800,000 times wider than our sun 380 times larger than the largest star we know today and Far Below its surface is a black hole growing rapidly as it devours billions upon billions of tons of matter per second normally Stars Are Born from gigantic clouds collections of thousands or millions of solar masses of mostly hydrogen in these clouds matter starts
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to accumulate around the densest spots inside as these spots get denser their gravitational pool intensifies and they grow faster eventually they generate so much heat and pressure that they ignite Fusion reactions and a new Star is Born but this puts a limit on their size nuclear fusion releases enough radiation energy that the surrounding gas cloud is blown away the new baby star can't gather more Mass from now on the star is living on the edge between two forces
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gravity pulling in trying to squash the star and radiation created by Fusion pushing outwards trying to blow the star apart after millions or billions of years is the core runs out of fuel and the balance brakes destroying the star but black hole stars were very very different the beasts of the early Universe a few hundred million years after the big bang when the universe was much smaller all the matter in existence was much more concentrated the universe was much
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denser and hotter Dark Matter was a dominant player forming giant structures called Dark Matter halos these dark matter Halos were so massive that they pulled in and concentrated unimaginably gigantic amounts of hydrogen gas becoming the birthplaces of the first stars and galaxies epic clouds of hydrogen formed some as massive as 100 Million Suns more than the mass of small galaxies in this unique environment that will never exist again the enormous gravitational pull of the Dark Matter
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Halos Drew gas into its Center and created extremely massive stars as we said before when A Star is Born it blows away the gas cloud that created it but these Titanic gas cloud in the early Universe was so large and massive that even after their birth more and more gas piled on the newborn star making it grow to unbelievable proportions the young star is forced to grow and grow and grow getting more and more massive until in some cases it reaches up to 10 million
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times the mass of our sun crushed by gravity its core gets hotter and hotter desperately pushing outwards trying to blow itself apart but to no avail there's too much mass and too much pressure the balance is impossible to uphold like a supernova run fast forward the core gets crushed into a black hole normally that would be the end today stars go supernova a black hole forms and things calm down but in this case the star survives its own death a tremendous explosion rocks the star from
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the inside but it's not enough the star is so large and massive that not even a supernova can destroy it but now it has a black hole for a heart it's tiny a few tens of kilometers in the center of a thing the size of the solar system the monster grows Stars Are Born from ever faster spinning and collapsing gas and so they also spin when a black hole is born from the core of a star it keeps its angular momentum this means that matter that gets drawn in doesn't just fall in a
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straight line but instead begins orbiting the black hole in smaller and smaller circles going faster and faster the result is an accretion disc where gas orbits at nearly the speed of light only a small amount of gas actually falls in at any given moment basically black holes put a lot of food on the table and only nibble at it but the matter trapped in the accretion disc doesn't have a good time friction and collisions between particles heated up to temperatures of millions of deg
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actively feeding black holes have accretion discs that are incredibly hot and Powerful this heat from the disc further restricts how much a black hole can devour just like the core of stars the super hot material creates radiation that blows away most of the food within its reach so even if a black hole had access to as much food as it desired it can only grow slowly a black hole embedded inside ins a black hole star is different the enormous pressure surrounding it pushes down matter
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directly into the black hole overcoming all restrictions on how fast it can consume this process is so violent and releases so much energy that the accretion disc becomes hotter and releases more radiation pressure than any star core ever could enough to push back against the weight of 10 million Suns an impossibly dangerous balance has been created millions of soda masses pushing in the angry radiation of a force-fed black hole pushing out for the next few million years the black hole
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star is consumed from within the black hole grows to thousands of solar masses and the bigger it gets the faster it eats which heats up the star even more and causes it to expand in its Final Phase the black hole star has become over 30 times wider than our solar system truly the largest star to ever exist in the the universe the intense magnetic fields at its core spew out Jets of plasma from the black hole's poles which Pierce through the star and shoot out into space turning it into a
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cosmic Beacon it must have been one of the most a inducing SES to ever exist in the universe but this also marks the end it becomes too stretched and the accretion disc within too powerful the parasite destroys its host blowing it apart a black hole hole with the mass of 100,000 Suns rips its way out to hunt for new prey while leaving behind nothing but a star carcass the super massive question if black hole Stars existed they could explain one of the greatest Mysteries of
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the universe the super massive black holes we see at the center of galaxies are just too big they shouldn't be possible black holes born from regular supernovas can be a few tens of solar masses at most and because of the process we explained before they grow slowly after that if black holes merge they can form slightly larger black holes of over a 100 solar masses it should take billions and billions of years to make black holes with hundreds of thousands or even millions of solar
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masses and yet we know that some super massive black holes already had 800 million solar masses only 690 million years after the big bang black hole stars are a sort of black hole cheek coat if they formed very early in our universe and the black holes that emerged from them were thousands of solar masses then they could be the seeds for super massive black holes these seeds could take root in the center of the earliest galaxies merging with others and drawing in enough matter
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to grow quickly and reliably very soon we may be able to verify their past existence the James web Space Telescope is turning its sens is to explore the farthest reaches of the universe looking back in time back to the early universe that we couldn't see before so with luck we might be able to witness glimpses of these tragic Titans in the brief moment between their formation and destruction until then let's do the visual Journey again just for fun stars are big black hole Stars bigger [Music]
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[Music] [Applause] [Music]
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