A night sky is strewn with billions of stars, and although theyseem very small bright points, in fact they are truly huge and amaze your imagination with your size. Each such "glowworm" in the sky is a huge plasma ball, in the depths of which there are powerful thermonuclear reactions, warming up stellar matter to thousands of degrees on the surface and up to millions - in the center. From a great distance, the stars seem insignificant, but very beautiful and radiant.
Currently only in our galaxyastronomical scientists number up to 400 billion stars, and in fact there are about 170 billion galaxies (in the accessible to study part of the Cosmos)! This number is almost impossible to imagine. To somehow navigate in this set, astronomers classify stars according to their luminosity, mass, size, and type. In the universe, you can meet such different stars as the red giant, the blue giant, the yellow dwarf, the neutron star, and so on. The largest of the stars are often called hypergigants. Those that are smaller are called supergiants. And sometimes it's difficult to understand which star is the biggest. After all, new stars and galaxies are constantly opening, and scientists have not yet learned to accurately determine their size.
The word "star" has a figurative meaning.But those who are accustomed to shine on the Earth (musicians, the biggest porn stars, Hollywood celebrities, outstanding artists and models) can not even dream of fending to greatness with the heavenly stars, they do not even dream of eclipsing the Sun by their own brilliance. But astronomers know: by the standards of the universe, it is only a yellow dwarf. There are much larger heavenly giants. Yes, for the most impatient, we will say at once that, unfortunately, not the Sun is the biggest star. But which is the largest?
The name of the largest star is UY from the constellation Shield.
The main difficulties in determining the comparativesize two. The first is huge distances existing in outer space. Remoteness does not allow you to accurately determine the size of the star, even the most modern instruments, and as the telescopes improve, the data is being refined all the time.
The second main difficulty is thatstars - dynamic astronomical objects, in them there is a mass of various processes. And some of the stars pulsate, changing their luminosity and magnitude. More recently, celestial bodies, bearing the title of the biggest stars, said goodbye to him for this reason. Especially "suffer" from this red giants, which are classified as the most huge. For this reason, the classification of stars in magnitude in any case will reflect the state of "in the sky" only at a given point in time. That is why the category of the largest stars will always be very relative and inconstant.
Все звезды во Вселенной имеют очень разные dimensions; they differ from each other, sometimes, very strongly, in tens, hundreds and more times. The sun is by no means the biggest star, but it can not be called the smallest. Its diameter is 1.391 million kilometers. And in this case, according to the stellar classification, it is the most typical "yellow dwarf"! Although this value seems huge, there are stars and a few times more. The largest (known to science) are Sirius, Pollux, Arcturus, Aldebaran, Rigel, Antares, Betelgeuse, Mu Cepheus and VY constellation of the Great Dog. The latter until recently was in the lead among all the famous stars.
The third largest star observedThe universe is considered WOH G64. This star is also ranked among the red giants. It belongs to the constellation Golden Fish of the Great Magellanic Cloud. The light of this star flies before us 163 thousand years. Perhaps the star has exploded for a long time, becoming a supernova, but we only learn about this after many thousands of years.
The diameter of the star-record holder is 1730 times the diameter of our star.
For a long time VY was considered the biggest star.constellation Canis Major. Its radius exceeds the Sun approximately 1300 times. Its diameter is 2 billion kilometers. This star is located in 5 thousand light years from our native solar system. One turn around VY would have taken the spacecraft 1200 years, if its speed was 800 kilometers per hour. If we reduce the diameter of the Earth to 1 centimeter and compare it, thus, with VY, then the diameter of the star would be 2.2 kilometers by such measures. Although the mass of the star is impressive not so - it is only 40 times heavier than the Sun. But the brightness of this star is incomparable with any celestial body, observed from Earth. It exceeds the sun by 500 thousand times.
For the first time VY Big Dog observed scientist JosephJérôme de Lalande, he wrote it down in his star catalog. The date of this remarkable event is March 7, 1801. It was stated that this VY has a seventh magnitude. After 46 years, observations were made, as a result of which it turned out that the star has a crimson color. Then it was discovered that this star has 6 discrete components, so it is most likely a multiple star. A multiple star is one that consists of several stars that are located close to each other, and is mistaken for one big star. At present, it is already known that the “discrete components” are actually bright areas of the nebula, which is located around the star. And this star is currently in second place in terms of magnitude.
With an impressive brightness, the density of the star is quite small. It is only five times the density of ordinary water. For comparison - the density of the substance of the Sun is 1.409 of the density of water.
Astronomers categorize this super giantunstable "old" stars and predict its explosion and transformation into a supernova in the next hundred thousand years. Fortunately for us, VY from the constellation Bolshoy Dog is so far from us that even when it explodes in a hundred thousand years, it will not hurt the solar system.
Behind the star are regular observations startingsince the 50s of the XIX century. During this time, the star has lost a significant part of its luminosity. Scientists believe that this process is associated with the loss of stellar matter, the star simply "burn out".
No matter how huge the previous star was, the pundits managed to discover an even more impressive one. And in our own Milky Way galaxy.
According to star catalogs, it passes as UY ofconstellation Shield. This abbreviation denotes changes in the brightness of the glow, so the star belongs to the class of variables with an approximate pulsation period of 740 days. If we compare the luminosity of a star-leader with the luminosity of our Sun in the visible spectrum with the naked eye, it is more than 120 thousand times. If we take into account the infrared radiation spectrum of these two stars, then we get an even more impressive figure - 340 thousand times!
Although it was first discovered by Germanastronomers in Bonn back in 1860, it was only possible to determine its true size in 2012, with the help of an American telescope located in the Atacama desert. Then she received a palm among the huge glowing beauties.
Звезда UY Щита удалена от Солнечной системы на nine and a half thousand light years, so its size can be determined only approximately. Its diameter is from 1.056 to 1.323 billion kilometers, which is 1500–1900 times the diameter of our star. But at the peak of pulsation (and, as we remember, UY from the constellation of the Shield belongs to the category of changeable stars) the diameter can reach 2000 solar diameters! This makes it the largest star in the Milky Way galaxy and in the entire investigated Universe.
For clarity:if you mentally place UY from the constellation of the Shield in place of our native Sun, then it will not only absorb the nearest planets, including Earth, but even “get” to Jupiter, and taking into account the highest radius estimate, it will also absorb Saturn's orbit.
Another interesting figure that will help to assess the entire degree of enormity of this largest star in the universe: in its volume you can fit five billion yellow dwarfs, like our Sun.
So, we can conclude that the largest star known to science is UY from the constellation of the Shield, and this was described in detail in this article.
