Encounters with black holes are the cosmic equivalent of a swimmer bumping into a great white
shark or a backpacker stumbling across a female grizzly bear with cubs nearby these monsters can
rip apart unlucky stars and scatter their remnants as easily as the massive shark devours its prey
still humans and other creatures do live to tell the tale after many of these dangerous liaisons
so is it possible for stars to survive a close encounter with the celestial beasts what if our
own son were threatened with destruction from an extreme wanderer astronomers like their hands have
not been full in recent months found time recently to pit diverse and highly detailed virtual stars
against simulated black holes and the results stretch the imagination welcome to Factnomenal
in today's video we dig deeper into the alphas of the universe
commonly known as black holes and reveal how their very real encounters with stars are likely to end
the greatest cosmic boogie man is the black hole a place in space so dense with a gravitational
pull so strong that even light cannot escape it is important to understand that black holes
were born of theory not observation in 1915 as the first world war was raging theoretical physicist
Albert Einstein completed 10 long years of work expanding his special theory of relativity late
in November the field equations of gravitation was published and he sent a copy to a colleague who
was trying to stay warm and alive in a battlefield trench on the Russian front the recipient was Carl
Schwartzchild a 42 year old accomplished theorist and mathematician who had joined the war effort
in just days Schwartz's child wrote back with the first written solution of how space-time as
Einstein theorized it is warped by the intense gravity of a theoretical megadense object
the black hole for years the black hole was little more than a mathematical curiosity and even the
name black hole was not applied until 1967 in 1971 the development of x-ray astronomy led
to the first physical black hole being discovered without the benefit of light escaping astronomers
relied on finding them through their effects on space and objects around them then came 2019
catching even a glimpse of an entity that does not allow light to escape its clutches is
to put it mildly a challenge and while astronomers have long seen evidence of
their existence it was only in 2019 that the first silhouette of an actual black hole was captured
it took well over a decade of work a team of international astronomers reimagined an
existing radio astronomy technique to produce a high resolution image of the mysterious structure
specifically by capturing the glowing gas that surrounds the black holes event horizon
that's the point of no return or more specifically the theoretical boundary
around a black hole beyond which no light or other radiation can escape
a place you should avoid using a vast array of telescopes from the south pole to Spain
along with imaging from several nasa spacecraft astronomers focused on m87 the supermassive black
hole at the center of the massive messier 87 galaxy 55 million light years from earth
a team member described it as akin to capturing an image of an orange on the surface of the moon
when the observations were completed astronomers did not have an image but rather
a mountain of data and that's not a metaphor as Dan Maron associate professor of astronomy at
the University of Arizona described it we had five petabytes of data recorded it amounts to more than
half a ton of hard drives transmitting that much data over the internet even with the fastest
speeds on earth was not even remotely feasible so researchers got it to western Massachusetts and
bonn Germany the old-fashioned way on airplanes what astronomers got for their efforts was the
first photograph of this mysterious and exotic monster at least of its immediate surroundings
and the beautiful effect it has on them that was thought to be unseeable and it gets better
researchers noted a significant amount of polarized light around the black hole so the
international team went back to work focusing on the light affected by the magnetized and hot
areas around the black hole astronomers early in 2021 revealed an even more startling image of m87
in it the object's accretion disk of hot gas and other diffuse materials are clearly
swirling around the black hole perhaps even more fascinating are the bright jets of energy and
matter that somehow escape before capture and are blown at least 5 000 light years from m87 center
most nearby matter is doomed to fall into the black hole but astronomers are trying
to determine how these jets make their getaway now let's delve into how astronomers created
a cosmic game of pinball to learn more about unfortunate meetings between stars and black holes
since thankfully we have no first hand experience with stars encountering black holes
an ambitious team of astronomers at the max Planck institute for astrophysics in Germany
did the next best thing a stunning simulation
the team led by theoretical astrophysicist Tejo Ryu became the first to combine the
physical effects of Einstein's general theory of relativity with realistic stellar density models
eight stars ranging from one tenth to ten times the density of our sun are sent to the
cosmic neighborhood of a huge black hole with a density one million times greater than the sun
astronomers sent the hapless stars on a u-shaped trajectory that brought them as close as 24
million miles away from the black hole closer than mercury is to the sun their interaction with
the black hole's gravity varied but for some the results were cataclysmic four of the crash test
dummy stars were ripped apart by the overwhelming gravity of the black hole in a process called
a tidal disruption event a rather innocuous description for having the matter of an object
shredded and swept into the monster's accretion disk of matter swirling around its horizon and
that's the pleasant part after which the black hole consumes the remnants completely however
some stars in the simulation were only partially disrupted and through their own gravity were
able to basically reassemble as they moved away from the black hole how and why did this happen
first of all when it's you against the black hole you should bet on the black hole
however astronomers now believe that there are factors that determine whether a star
is completely destroyed by a close encounter with these cosmic monsters in the simulation
four stars survived the close approach and size had little to nothing to do with their survival
the star most like the sun made it through along with those that had 0.15 0.3 and 0.7 solar masses
the stars that were 0.4 0.5 3 and 10 times the mass of the sun were shredded and gone it seems
intuitive that the larger stars have more matter to lose and thus have better chances of escaping
being devoured by the black hole but the results showed otherwise turns out the key factor for
living another day was density all four of the survivors of their encounters were the higher
density stars that managed to keep more of their matter intact and as we mentioned the star modeled
after our sun also survived which is good news considering that the closest black hole to you
and i is sagittarius a the supermassive black hole at the center of the Milky Way it resides roughly
26,000 light years away which is just around the corner cosmically speaking the team of
astronomers wildly succeeded in getting a better understanding of how tidal disruptions occur
and their effects on stars that unwittingly find themselves too close to black holes
when we think of black holes much in the way we consider great white sharks and angry
mother grizzlies we tend to only consider their destructive influences on their neighbors but
astronomers have found a whole new side of these mysterious and perhaps misunderstood entities
in fact researchers say that the act of heating and ejecting a galaxy's gas which makes it more
difficult for the larger galaxies to produce new stars has the exact opposite effect on
satellite galaxies in a study published in the peer review journal nature in June 2021
astronomers revealed data from over 124,000 satellite galaxies on the outskirts of nearly
30,000 large galaxies that's been collected for over two decades each of the large galaxies is
believed to have a supermassive black hole in its core the energy of these giant black holes blows
gases and jets far away from the galaxy itself where the now intergalactic gas forms bubbles
in galaxy clusters small satellite galaxies pass through these bubbles
and astronomers have observed a very interesting phenomenon a baby boom of new stars see these
satellite galaxies travel through intergalactic gases surrounding the much larger central galaxy
and in the encounters have their own gases swept away astronomers call this ram pressure stripping
and its ultimate effect is to leave these satellite galaxies void of star-making materials
and thus barren but those jets of gases blown outwards by black holes effectively clear away
gases that cause the satellite galaxies to have their star-making material swept away
what's left behind is a void an area clear of gases that allow these smaller galaxies
to continue to reproduce astronomers found these galaxies are up to five percent less likely to
have had their star formation quenched perhaps the finest defense of misunderstood black holes was
tweeted by Christa Smith a NASA earth and space sciences fellow at Goddard space flight center
smith urged cosmic critics to stop demonizing supermassive black holes they aren't lurking
in galactic centers that's their home they built it keep a respectful distance and you'll be fine
they are just beautiful giants maybe but after seeing the breathtaking encounters
between stars and black holes as simulated the advice about keeping a respectful distance is
easy to understand so what do you think about these dynamic close encounters between black
holes and relatives of our sun are 26,000 light years between earth and our galactic core a bit
too close for comfort tell us in the comments and as always thank you for watching Factnomenal