10 BIGGEST Star Discoveries in Space | Space Discoveries

   there is nothing more visible or  recognizable in the vast night sky than  the stars sparkling in the heavens above  but what do we know about stars aside  from them being pretty to look at  how big is our sun compared to other  stars we found so far  welcome to  and today we're  exploring the 10  biggest star discoveries in space  what is a star stars are immense  luminous balls of burning hot gas called  plasma  they're held together by the  gravitational force exerted on the atoms  that make up its huge  mass from the perspective of earth they  look  tiny but it's only because they're so  far away in fact our closest star alpha  century is 4.36  light years or a trillion kilometers  away  this means that light traveling at  almost 300 000 kilometers per second  would still take  years to get there to put it into  perspective a space shuttle sent out  from earth would take a little  over a hundred years to reach the  nearest star to our own sun  and they would be there for 4.367 years  before the earth receives broadcast  announcing their arrival  the energy produced by a star is emitted  as light heat  energy and radiation as a byproduct of  the nuclear fusion happening at its core  four hydrogen atoms are squeezed  together so tightly by the incredible  gravity and weight of mass  that they're transformed into the two  protons and two neutrons that form a  helium nucleus  stars literally exist because of the  balance between two opposing forces  the gravity formed by their mass trying  to make the star shrink  versus the heat and energy released by  the internal reaction  trying to make it grow how are stars  formed  clouds of gas and dust in space  materialized after the big bang  13 billion years ago as matter began to  be drawn together by gravity  these clouds are the birthplace of the  stars as the gas and particulate matter  begin to get closer together  parts of the cloud shrink in size and  begin to collapse  forming focal points called cores within  the cloud  the gravity in the cores increases to  the point where it gets so dense that  nuclear fusion begins and with the  byproduct given off as heat working  against its own gravity  a star is born this process is known as  stellar ignition and the initial burst  of light made by a newly formed star  blows away much  of the surrounding cloud particles but  not all the remainder of the material  left behind forms planets over time  how they're classified the most logical  way to sort stars is to group them based  on their mass and temperature  generally the more mass a star has the  more intense the nuclear fusion reaction  inside hence the more heat it pumps out  the scale progresses from o through b a  f  g k and m where o class stars exceed 30  000 degrees celsius  and those in the m group with 3 000  degrees celsius or less  the temperature of a star causes it to  burn at a different color  similar to superheating a piece of metal  stars range from red  orange yellow to white and all the way  up to blue  our own sun is a class g yellow door and  sits in the range of 6  000 to 7 000 degrees celsius  stars are extremely variable in size a  neutron star is just 20 to 40  kilometers in diameter where a white  dwarf is roughly the size of the earth  the largest supergiants can be more than  two million kilometers in diameter which  is more than fifteen hundred times the  size of our sun  how long do they live the lifespan of a  star is directly proportionate to the  nuclear fusion reaction at its core  supergiant blue stars burn through their  fuel very quickly and can last just a  few hundred thousand years in addition  to the hydrogen to helium nuclear fusion  they produce heavy metals  eventually they give way and form a red  supergiant the biggest class of star in  the universe  this red supergiant expands until it  reaches a tipping point causing a  violent stellar explosion called a  supernova and for a brief moment emits  so much light it outshines the rest of  the universe  the end result can go one of two ways  the formation of a particulate ejecting  super dense neutron star  or the hungry infinite gravity of a  black hole  as average-sized yellow stars approach  the end of their life cycle  they increase in size by up to a  thousand times their dwindling fuel  supply turning them into red  giants when there is no energy left the  star begins to lose  layers and forms a complex structure  called a planetary nebula  the end result is the formation of a  white dwarf an extremely  dense star on the other hand smaller red  stars burn at a much slower rate and can  exist for billions of years  as they die out they form a rather  uninteresting brown dwarf star  how are they measured measuring a star  is  tricky business it's a moving goal post  as stars have no definitive surface edge  to use as a marker for the origin and  termination of the measurement axis  there's no cosmic ruler that astronomers  can use so instead a star is measured by  its angular size  which is a width measured in degrees the  hard part is that stars expand and  contract as a result of the ebbs and  flows of the nuclear fusion reaction and  as a result their brightness changes  which gives stars their notorious  twinkle  at the end of the day all you can do is  average out a star's size  or calculate it based on best guesses  the term used to measure a star is a  solar radius based off the radial  distance of our own yellow sun  so let's venture through the top 10  biggest stars we've discovered so far  number 10 kw sagittari  1460 solar radii  sitting 7 800 light years from earth is  kw sagittari  a star 1 460 times the size of our sun  if it were the central star in our solar  system its borders would exceed the  orbit of the planet mars  despite being much larger it burns at a  little over half the temperature of the  sun  number nine ky cygni 1420 to 2850 solar  radii  the constellation cygnus is 5 000 light  years from earth  and ky cygni is the biggest star in the  cluster  unfortunately our field of view is  blocked so we can't visibly see it  instead we have to calculate its size  based on the electromagnetic radiation  and radio waves it emits  number eight rw cephe 1600 solar radii  we can see the constellation cepheus  from the northern hemisphere of the  earth  it contains some whopper stars and rw  cephei isn't even the biggest of the  bunch  it's still an impressive 1600 solar  radii and if put in our solar system its  outer margins would extend far beyond  jupiter  number seven v 354 cephe  1520 solar radii  at 9000 light years away we have v354  cephe coming from a group of jumbo-sized  superheated stars in the cepheus  constellation  it's the one exception to the rule as it  has become cool due to its age  meaning it could be well on its way to  an explosive supernova status  number six who g64  1540 solar radii  this poor who g64 star has had a hard  life  it's actually located in a dwarf galaxy  called the large magellanic cloud that  orbits the milky way  it's nearing its supernova death and has  grown to a huge  size expelling enough mass and material  to form between  three and nine of our solar systems  number five  v838 monoceratus 380 to 1970 solar radii  v838 monocerotis is an extremely  unstable star  it pulses expanding and contracting  wildly as the reaction at its core burns  out of control  as a result its size changes each time  it's measured by the hubble space  telescope  number four mu cephe 1650 solar radii  with a luminance 38 000 times greater  than that of our own sun  it's part of a huge group of stars in  the cepheus constellation  number three vv cephe a 1675  solar radii vv cephe a is a part of an  eclipsing binary star system and is  quite unique  its companion blue star is slightly  smaller but will one day eventually  swell to become a red supergiant just  like its counterpart  number two vy canis majoris  1800 to 2100 solar radii  the massive v y canis majoris was the  largest known star for a very long time  if put in the center of our solar system  it would take up enough room to nearly  reach  saturn the constellation canis majoris  contains an  inexplicably large number of  variable-sized twinkling stars  and finally number one stevenson 218.  2150 solar radii  this is the biggest star we know of  stevenson 218.  it is so large that it has a volume 10  billion times bigger than our sun  placed in our solar system it would  engulf saturn and  almost reach uranus