astronomers have discovered what may be the  universe's version of Shrek a giant ogre of  

a galaxy so large and scary that cosmic  villagers surely run away at first sight  

they've even named it Alcyoneus after a greek  mythical giant who fought Hercules and whose name  

literally means mighty ass at 16.3 million light  years wide the Alcyoneus galaxy has a diameter 160  

times wider than the milky way and four times  that of the previous title holder ic1101  

welcome to Factnomenal in today's video we  fly across the cosmos to see the largest  

radio galaxy ever discovered and how its  nature is befuddling astronomers the world over

Alcyoneus is a whale of an oddity a giant  in a universe of giants just how large is it  

time to get out your measuring sticks  because this is gonna get tricky  

that's quite big let's talk about parsecs in the  first star wars movie that some blasphemously call  

a new hope Han Solo boasts that the millennium  falcon may the Kessel run in less than 12 parsecs  

but this makes no sense as a parsec is unit of  measurement not time either way a parsec measures  

3.26 light years and the nearest star to earth  besides the sun of course is Proxima Centauri  

about 1.3 parsecs away but we need to move on to  megaparsecs which measure 3.26 million light years  

our nearest galaxy andromeda is less than 0.9  megaparsecs away so a megaparsec is huge Alcyoneus  

for perspective is at least 5.04 megaparsecs  wide if han solo had understood parsecs or  

units of distance and not time he would know that  this giant radio galaxy measures 400 000 times as  

wide as his legendary kessel run for even more  perspective ic 1101 the previous record holder  

now relegated to second place is not even two  measly megaparsecs wide a runt by comparison

picture this the Alcyoneus galaxies roughly  3 billion light years from earth while our  

friendly neighborhood andromeda galaxy is by  comparison a miniscule 2.5 million light years  

away andromeda is also the furthest object humans  can see with the naked eye and when you see it  

you're witnessing light that has started its  journey to your backyard long before modern  

humans ever existed to see andromeda you must give  your eyes quite a while to adjust to the dark sky  

perhaps an hour and then you should be able to  detect a faint and fuzzy patch of light in the  

constellation pegasus ah there it is andromeda  however if the radio signals we received from  

alcianeus were light instead it would be as large  as the moon in our night sky and 3 billion light  

years away as the researchers note astronomical  pictures are taken from a single viewpoint  

earth and therefore don't contain depth as a  result scientists can only measure a part of  

the radial galaxy length a low estimate of  the total length but even that lower bound  

is comparable to 100 milky ways in a row so  yes our cosmic shrek is mind-bogglingly huge

lofar or the low frequency array is a network of  around twenty thousand radio antennas in europe  

that together create the world's largest radio  telescope laden university phd student martine  

oe and his phd supervisors were studying the  distribution of cosmic web material filaments  

when they stumbled across a spectacular discovery  they called a stroke of luck and it was hiding in  

plain sight in the lynx constellation this stroke  of luck has already disproved some long-held ideas  

about limits to growth of radio galaxies and  very likely will shed light on mechanisms that  

drive radio galaxy growth but before these it  first set in motion a massive international search  

by astronomers in the netherlands uk and france  to collect the radio light from this discovery  

why radio light and not light most if not all  large galaxies have supermassive black holes  

in their centers and matters pulled into these  monsters in a pattern not entirely different  

from the water in your bathroom water does not  simply pour straight down a drain but as it  

gets closer its angular velocity increases and it  swirls the earth's rotation influences water with  

the coriolis effect at least slightly though in  reality physicists say the swirling is more of an  

accidental twist caused by the irregularities in  the starting flow either way when matters dragged  

into a black hole's event horizon that lovely  point of no return when you need not worry about  

what you're going to wear tomorrow it circles  like that water in your sink and some of it is  

violently ejected once matter crosses the event  horizon it's lights out but before that point the  

black hole shoots astrophysical jets in opposite  directions from the galactic center or active  

galactic nuclei traveling at almost the speed of  light the material heats and dissolves into plasma  

which then emits radio light and this radio light  is detectable by lofar scientists were then able  

to reprocess a set of already existing images in  a way that subtle patterns were suddenly obvious  

and there it was that's how this ridiculously  large but dim alcianeous galaxy was found

despite alciania's mind-boggling distance  from earth the giant looms as large as  

the moon in the sky an indication the  structure has to have a record length  

the fact that the radio eyes of the  lofar telescope only saw the giant  

just now is because the plumes are relatively  faint by reprocessing a set of existing images  

in such a way that subtle patterns stood out the  scientists were suddenly able to spot the giant  

a giant hiding in otherwise plain sight right  in the middle of our sky like finding a gigantic  

but invisible needle in a haystack our own  milky way has at least one plume streaming  

from near its center outwards since we're  residents here and as of yet have not left  

the galaxy for a better vantage point to see  such things they are notably difficult to detect

alcianeus is simply the largest known structure  in the universe of galactic origin how this  

interstellar ogre grew so ridiculously large  is a mystery astronomers are trying to decipher  

despite initial suspicions that alcianea's  supermassive black hole must be unusually large  

even for something called supermassive data from  lofar indicates it's relatively normal compared  

to other radio galaxies if not small meaning if  all it took was a black hole of the size of the  

one in alcianeus to produce a comparably enormous  radial galaxy there would be an incredible number  

of them and there aren't so out of a galaxy  of quite limited density what's causing these  

tremendous sin baffling plumes clearly as oa  notes there are incredible and thus far unknown  

processes at work in alcianeus galaxies are  not just peaceful collections of stars and dust  

but many feature violent spectacular processes  like glowing jet streams and plumes that reach  

far out into the depths of space many millions  of light years or hundreds of times their size

astronomers believe that alcianeus may offer new  clues as they continue to unravel the structure of  

the universe particularly about the cosmic web  this is the incredibly complex and gargantuan  

scaffolding network of invisible gas and dark  matter woven through the cosmos some believe  

these colossal filaments are the reason just about  everything in the universe spins have you ever  

wondered about that the plumes of alcianeus are so  large so rarefied that chances are high they'll be  

used to learn more about the cosmic web that's so  hard to see but connects the universe if only we  

could visit and see our cosmic shrek up close  and while it would be a difficult trip to make  

berlin has a sculpture of the mythological giant  at its famous pergamon museum Alcyoneus that is  

not shrek so what do you think about having a new  champion of the universe for galactic structures  

does Alcyoneus hold promise for exciting new  discoveries about the enchanting but elusive  

cosmic web please tell us in the comments and  as always thank you for watching Factnomenal