Stars are large celestial bodies of hot plasma, the dimensions of which can amaze the most inquisitive reader. Are you ready to develop?
It’s worth noting right away that the rating was compiled taking into account those giants that humanity already knows about. It is possible that somewhere in outer space there are stars of even larger dimensions, but they are located at a distance of many light years, and modern equipment is simply not enough to detect and analyze them. It is also worth adding that most stars will cease to be such over time, because they belong to the class of variables. Well, don’t forget about the possible errors of astrologers. So...
Top 10 biggest stars in the Universe
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Opens the ranking of the largest stars in the Betelgeuse Galaxy, whose dimensions exceed the radius of the sun by 1190 times. It is located approximately 640 light years from Earth. Comparing with other stars, we can say that it is at a relatively short distance from our planet. The red giant may go supernova in the next few hundred years. In this case, its dimensions will increase significantly. For good reasons, the star Betelgeuse, occupying the last place in this ranking, is the most interesting!
RW
An amazing star, attracting with its extraordinary color of glow. Its size exceeds the dimensions of the sun from 1200 to 1600 solar radii. Unfortunately, we cannot say exactly how powerful and bright this star is, because it is located far from our planet. Leading astrologers from different countries. Everything is due to the fact that it regularly changes in the constellation. Over time, it may disappear altogether. But it still remains in the top of the largest celestial bodies.
Next in the ranking of the largest known stars is KW Sagittarius. According to ancient Greek legend, she appeared after the death of Perseus and Andromeda. This suggests that this constellation was discovered long before our appearance. But unlike our ancestors, we know about more reliable data. It is known that the size of the star exceeds the Sun by 1470 times. Moreover, it is located relatively close to our planet. KW is a bright star that changes its temperature over time.
It is currently known for sure that the size of this large star exceeds the size of the Sun by at least 1430 times, but it is difficult to obtain an exact result because it is located 5 thousand light years from the planet. Even 13 years ago, American scientists provided completely different data. At that time, it was believed that KY Cygni had a radius that increased the size of the Sun by a factor of 2850. Now we have more reliable dimensions relative to this celestial body, which are certainly more accurate. Based on the name, you understand that the star is located in the constellation Cygnus.
A very large star included in the constellation Cepheus is V354, whose size is 1530 times larger than the Sun. Moreover, the celestial body is located relatively close to our planet, only 9 thousand light years away. It does not differ in particular brightness and temperature compared to other unique stars. However, it is a variable luminary, therefore, dimensions may vary. It is likely that Cepheus will not last long in this position in the V354 ranking. Most likely, the size will decrease over time.
A few years ago it was believed that this red giant could become a competitor to VY Canis Major. Moreover, some experts conventionally considered WHO G64 to be the largest star known in our Universe. Today, in the age of rapid development of technology, astrologers have managed to obtain more reliable data. It is now known that the radius of Doradus is only 1550 times larger than the Sun. This is how huge errors are permissible in the field of astronomy. However, the incident can easily be explained by distance. The star is located outside the Milky Way. Namely, in a dwarf galaxy called the Vast Magellanic Cloud.
V838
One of the most unusual stars in the Universe, located in the constellation Monoceros. It is located approximately 20 thousand light years from our planet. Even the fact that our specialists managed to detect it is surprising. V838 was even larger than Mu Cephei. It is quite difficult to make accurate calculations regarding dimensions, due to the enormous distance from the Earth. Speaking of approximate size data, they range from 1170 to 1900 solar radii.
The constellation Cepheus contains many amazing stars, and Mu Cephei is considered proof of this. One of the largest stars is 1660 times larger than the Sun. The supergiant is considered one of the brightest in the Milky Way. About 37,000 times more powerful than the illumination of the star we know best, the Sun. Unfortunately, we cannot say unambiguously at what exact distance from our planet Mu Cephei is located.
Stars are huge balls of hot plasma. The size of some of them will amaze even the most unimpressive reader. So, are you ready to be surprised?
Below is a list of the ten largest (in diameter) stars in the Universe. Let’s immediately make a reservation that this ten is made up of those stars that we already know. With a high degree of probability, in the vastness of our vast Universe, there are luminaries with an even larger diameter. It is also worth noting that some of the presented celestial bodies belong to the class of variable stars, i.e. they periodically expand and contract. And finally, we emphasize that in astronomy all measurements have some error, so the figures indicated here may differ to an insignificant degree for such a scale from the actual sizes of stars.
1. VY Canis Majoris
This red hypergiant has left all its competitors far behind. The radius of the star, according to various estimates, exceeds the solar one by 1800-2100 times. If VY Canis Majoris was the center of our solar system, its edge would come very close to the orbit. This star is located about 4.9 thousand light years in the constellation Canis Major.
2. VV Cephei A
The star is located in the constellation Cepheus at a distance of about 2.4 thousand light years. This red hypergiant is 1600-1900 times larger than ours.
3. Mu Cephei
Located in the same constellation. This red supergiant is 1650 times larger than the Sun. In addition, Mu Cephei is one of the brightest stars. It is more than 38,000 times brighter than our star.
4. V838 Unicorn
This red variable star is located in the constellation Monoceros at a distance of 20 thousand light years from Earth. Perhaps it shone even more than VV Cephei A and Mu Cephei, but the huge distance separating the star from our planet does not allow at the moment make more accurate calculations. Therefore, it is usually assigned from 1170 to 1970 solar radii.
5. WHO G64
It was previously thought that this red hypergiant could rival VY Canis Majoris in size. However, it was recently discovered that this star from the constellation Doradus is only 1540 times larger than the Sun. The star is located outside the Milky Way in the dwarf galaxy Large Magellanic Cloud.
6. V354 Cephei
This red hypergiant is quite a bit smaller than WHO G64: it is 1520 times larger than the Sun. The star is relatively close, only 9 thousand light years from Earth in the constellation Cepheus.
7. KY Swan
This star is at least 1420 times larger than the Sun. But, according to some calculations, it could even top the list: the argument is serious - 2850 solar radii. However, the real size of the celestial body is most likely close to the lower limit, which brought the star to the seventh line of our rating. The star is located 5 thousand light years from Earth in the constellation Cygnus.
8. KW Sagittarius
Located in the constellation Sagittarius, the red supergiant is 1460 times the radius of the Sun.
9. RW Cepheus
There is still controversy over the dimensions of the fourth representative of the Cepheus constellation. Its dimensions are about 1260-1650 solar radii.
10. Betelgeuse
This red supergiant is located just 640 light-years from our planet in the constellation Orion. Its size is 1180 solar radii. Scientists believe that Betelgeuse can be reborn at any moment, and we will be able to observe this interesting process almost “from the front row.”
The comparative sizes of stars can be estimated from this video:
My six-year-old daughter is a question-asking machine. A couple of days ago we were driving from school and she asked me about nature. One of her questions was, " Which star is the largest in the Universe??" I gave a simple answer. "The universe is a big place," I said, "and there is no way we can know which star is the biggest"But that's not the real answer.
Radius and mass of the Sun:
When talking about star sizes, it's important to first look at ours for a sense of scale. Our star has a diameter of 1.4 million kilometers. This is such a huge number that it is difficult to get a sense of scale. By the way, the Sun accounts for 99.9% of all matter in our planet. In fact, you could fit a million inside the volume of the Sun.
Using these values, astronomers created the concepts of "solar radius" and "solar mass", which they use to compare stars of larger or smaller size and mass to our Sun. The solar radius is 690,000 km and the solar mass is 2 x 10 30 kg. This is 2 nonillion kilograms, or 2,000,000,000,000,000,000,000,000,000,000 kg.
Illustration of a Morgan-Keenan spectral diagram showing the differences between main sequence stars. Credit: Wikipedia Commons.
It's also worth considering the fact that our Sun is quite small, a G-class main sequence star (specifically a G2V star), which is commonly known as being on the smaller side of the size chart (see above). Although the Sun is definitely larger than the most common M-class stars, or red dwarfs, it is itself a dwarf (no pun intended!) compared to blue giants and other spectral classes of stars.
Classification:
Stars are grouped based on their characteristics, such as spectral type (i.e. color), temperature, size and brightness. The most common classification method is called the Morgan-Keenan (MK) system, which classifies stars based on temperature using the letters O, B, A, F, G, K and M, with O being the hottest stars and M being the coldest. Each letter class is divided into numerical subclasses from 0 (hottest) to 9 (coldest). That is, the hottest stars are O1, and the coldest stars are M9.
In the Morgan-Keenan system, luminosity class is added using Roman numerals. This is done based on the specific width of absorption lines in the star's spectrum, which vary depending on the density of the atmosphere, which distinguishes giant stars from dwarfs. Luminosity has classes 0 and I as applied to hyper- and supergiants; classes II, III and IV as applied to bright, normal giants and subgiants, respectively; class V for main sequence stars; and classes VI and VII apply to subdwarfs and dwarfs.
Hertzsprung-Russell diagram showing the relationship between star color, luminosity, and temperature. Credit: astronomy.starrynight.com
There is also a Hertzsprung-Russell diagram relating to stellar classification by absolute magnitude (i.e. true brightness), luminosity and surface temperature. The same classification is used for spectral types, ranging from blue and white at one end to red at the other, which then groups stars together by absolute magnitude, placing them on a two-dimensional graph (see above).
On average, O-class stars are hotter than other classes of stars, reaching effective temperatures of up to 30,000 Kelvin. At the same time, they are larger and more massive, reaching sizes of more than 6.5 solar radii and up to 16 solar masses. At the lower end of the diagram, K- and M-class stars (orange and red dwarfs) tend to be cooler with temperatures ranging from 2400 to 5700 Kelvin, which is 0.7 - 0.96 from and somewhere between 0.08 - 0. 8 of solar mass.
Based on the full classification of our Sun (G2V), we can say that it is a main sequence star with a temperature of about 5800 Kelvin. Now let's look at another famous star system in our galaxy - Eta Carinae- a system containing at least two stars located at a distance of 7500 light years from us in the direction of the constellation Carina. The main star of this system is estimated to be 250 times larger than the Sun, has a mass of at least 120 solar masses, and is a million times brighter than the Sun, making it one of the largest and brightest stars ever observed.
Eta Carinae, one of the most massive known stars, is located in the constellation Carina. Credit: NASA
There is currently debate about the size of this star. Most stars emit a stellar wind (the same as wind), losing mass over time. But Eta Carina so large that it sheds 500 times more mass annually. With such mass loss, it is difficult for astronomers to accurately measure where the star ends and the stellar wind begins. In addition, scientists believe that Eta Carina will explode in the not so distant future, and it will be the most spectacular thing people have ever seen.
In terms of sheer mass, first place goes to star R136a1, located at a distance of 163,000 light years from us. It is believed that this star may contain 315 solar masses, which is a mystery to astronomers as they believe that stars can only contain a maximum of 150 solar masses. The answer lies in the fact that star R136a1 was most likely formed when several massive stars merged together. Needless to say, R136a1 could explode like .
In terms of big stars, a good (and popular) example is Betelgeuse. Located in the shoulder of Orion, this famous supergiant has a radius of approximately 950-1200 solar radii, at which radius the Sun would be absorbed into our Solar System. In fact, whenever we want to put the size of our Sun into perspective, we often use Betelgeuse to do this (see below).
However, even after we use this lumbering red giant to compare the Sun to larger stars, there are still larger stars left. Let's consider star WOH G64, a red supergiant located in the Large Magellanic Cloud, approximately 168,000 light-years from Earth. With a diameter of 1540 solar radii, this star is currently the largest star known to us in the Universe.
But there is also RW Cepheus, an orange hypergiant in the constellation Cepheus, located 3500 light years from Earth and measuring 1535 solar radii in diameter. Star Westerland 1-26 (Westerlund 1-26) Extraordinarily large, it is a red supergiant (or hypergiant) located in the stellar supercluster Westerlund 1 at a distance of 11,500 light years from us and measuring 1,530 solar radii in diameter. Meanwhile, stars V354 Cephei and VX Sagittarii also have huge dimensions of 1520 solar radii in diameter.
The largest star is UY Scuti (UY Scuti)
The title of the biggest star in the Universe(that we know of) comes down to two contenders. For example, UY Shield Currently at the top of the list, located 9,500 light-years away in the constellation Scutum, this bright red supergiant and pulsating variable star has an average radius of 1,708 solar radii - or 2.4 billion kilometers (15.9 AU) , thereby giving it a volume of 5 million volumes of the Sun.
However, this average estimate includes an error of ±192 solar radii, which means the radius of this star could be either 1900 or 1516 solar radii. The lower bound places it on par with V354 Cephei and VX Sagittarius. Meanwhile, the second largest star in the list of possible biggest stars- This NML Cygni (NML Cygni), a semi-regular variable red hypergiant star located in the constellation Cygnus at a distance of 5300 light years from Earth.
An enlarged image of the red giant UY Scuti. Credit: Rutherford Observatory/Haktarfone.
Due to the location of this star in , it is heavily obscured by dust. As a result, according to astronomers, its size can range from 1642 to 2775 solar radii, which means it could become the largest star known in the Universe(with a margin of about 1000 solar radii), or in fact the second largest, keeping up with UY Shield.
Just a few years ago the title most big stars wore VY Canis Majoris(VY Canis Majoris), a red hypergiant in the constellation Canis Major, located 5000 light years from Earth. Back in 2006, Professor Roberta Humphrey of the University of Minnesota calculated the upper limit of its size to be 1540 times larger than the Sun. Its average mass, however, was 1420 solar masses, which places it in 8th place behind V354 Cepheus and VX Sagittarius.
The above were listed biggest stars, which we know about, but most likely there are dozens of larger stars hidden by dust and gas, so we don’t see them. But even if we can't detect these stars, we can speculate about their likely size and mass. So how big can stars be?? Once again, Professor Roberta Humphrey from Minnesota gave the answer.
Comparison of the sizes of the Sun and VY Canis Majoris, a star that once held the title largest known star in the universe. Credit: Wikipedia Commons/Oona Räisänen.
As she explained in her article, largest stars in the universe- the coldest. Therefore, although Eta Carina is the brightest star we know of, it is extremely hot (25,000 Kelvin) and therefore only 250 solar radii in diameter. The largest stars, on the contrary, will be cold supergiants. As in the case VY Canis Majoris, which has a temperature of 3500 Kelvin, and a really large star will be even cooler.
At 3000 Kelvin, Humphrey estimates the cool supergiant would be 2600 times the size of the Sun. This is below the upper limit of estimates for NML Swan, but above the average ratings for both NML Swan, and for UY Shield. Therefore, this is the upper limit of the star (at least theoretically and based on all the information we have to date).
But as we continue to peer at the Universe with all our telescopes and study it with robotic spacecraft and manned missions, you are sure to find new amazing things that will continue to amaze us!
And be sure to check out this amazing animation below, which shows the sizes of various objects in space, from tiny to star UY Scuti. Enjoy!
Title of the article you read "Which star is the largest in the Universe?".
Look at the night sky and see that it is filled with stars. But with the naked eye, only a microscopic fraction of them can be seen. There are up to 100 billion stars in one galaxy alone, and there are even more galaxies in the Universe. Astronomers believe that there are about 10^24 stars in the world. These powerful powerhouses come in a variety of colors and sizes - and next to many of them, our Sun looks tiny. But which star will be the true giant of the heavens? We should start by defining what we mean by a giant. Will it be the star with the largest radius, for example, or the one with the largest mass?
Galactic giants
The star with the largest radius is probably UY Scuti, a variable bright supergiant in the constellation Scutum. Located 9,500 light-years from Earth and composed of hydrogen, helium and other heavier elements almost the same composition as our Sun, this star has a radius of 1,708 (give or take 192) times around it.
The star's circumference is about 7.5 billion kilometers. You'd have to fly a plane for 950 years to circle it completely - and even light would take six hours and 55 minutes. If we replaced our Sun with this one, its surface would be somewhere between the orbits of Jupiter and Saturn. Of course, there would be no Earth then.
Given its enormous size and possible mass 20-40 times that of the Sun (2-8×10³¹kg), UY Scuti would have a density of 7×10⁻⁶ kg/m³. In other words, it is billions of times less dense than water.
Basically, if you were to put this star in the biggest water bath in the universe, it would theoretically float. Being a million times less dense than the Earth's atmosphere at room temperature, it would also hang in the air like a balloon - if, of course, enough space was found for it.
But if these incredible facts have already managed to surprise you, we haven't even started yet. UY Shield is certainly a big star, but far from a heavyweight. The king of heavyweights is the star R136a1, located in the Large Magellanic Cloud, 165,000 light years away.
Massive attack
This star, a sphere of hydrogen, helium and heavier elements, is not much larger than the Sun, 35 times its radius, but 265 times more massive - which is remarkable considering that in the 1.5 million years of its life it has already lost 55 solar masses.
The type of Wolf-Rayet stars is far from stable. They look like a fuzzy blue sphere with no clear surface, blowing incredibly powerful stellar winds. Such winds move at 2,600 km/s - 65 times faster than the Juno probe, the fastest man-made object.
As a result, the star loses mass at a rate of 3.21×10¹⁸ kg/s, equivalent to Earth's loss in 22 days.
Such cosmic rock stars burn out quickly and die quickly. R136a1 emits nine million times more energy than our Sun and would appear 94,000 times brighter to our eyes if it took its place. In fact, it is the brightest star discovered.
its surface is over 53,000 degrees Celsius (), and such a star will live no more than two million years. Her death will be marked by a colossal supernova explosion, which will not even leave a black hole behind.
Of course, next to such giants, our Sun looks insignificant, but, again, it will also grow as it ages. In about seven and a half billion years, it will reach its maximum size and become a red giant, expanding so much that the Earth's current orbit will be inside the star.
And yet we found these stars by studying only a small fraction of the Universe. What other miracles await us?
Do you know what is the biggest star in the Universe? The Sun, which is the main luminary and the basis of our planetary system, is not even among the ten largest and brightest objects in outer space. At the same time, this rating is constantly undergoing changes due to the development of astronomical research technologies.
You will learn about the largest and bright stars discovered so far. We will tell you about their main features and location, and also compare these luminaries with the Sun.
The largest star known
The name of the largest star in the Universe is UY Scuti (in Latin - UY Scuti). It is located in the constellation of the same name, 9.5 thousand light years from the Solar System. The giant object was discovered back in 1860 by astronomers from the German city of Bonn.
Physical parameters
The largest star in the Universe has a radius 1,708 times that of the Sun. And at the peak of the pulsation it expands to 1900 Suns. But, despite its gigantic size, UY Shield is quite lightweight. It is constantly losing large amounts of matter and at the moment its mass is equal to the mass of ten Suns.
UY Scuti is the second brightest in all of outer space. According to this indicator, it exceeds our luminary by 340 thousand times. But so much gas and dust has accumulated around it that it cannot be seen in the sky with the naked eye (visible magnitude level 11). At the same time, its brilliance is not constant, which makes UY Scuti a variable luminary.
The heaviest star
First place on the pedestal of the most massive stars in the Universe is occupied by R136a1, located in the Tarantula Nebula. This region of plasma is located in the Large Magellanic Cloud galaxy, 163 thousand light years away from the Milky Way.
R136a1 was discovered by British astronomer Paul Crowther and his research team in 2010. While studying the RMC 136a cluster, they discovered an incredibly large object. The luminary turned out to be the largest in this formation, and in the entire observable Universe.
Characteristics of the star giant
R136a1 is a blue hypergiant. This is a rare class of stars that have the largest size, mass and brightness, but have a short lifespan.
The mass of the stellar giant exceeds the solar one by 315 times. This is one of the mysteries for scientists, because... Previously it was believed that no luminary could have a mass greater than 150 solar masses. But this rule applies to primary celestial bodies formed from helium-hydrogen clouds. R136a1 most likely formed through the merger of several large objects.
The radius of this star is 36 solar, and its brightness exceeds the Sun by almost 9 million times. Due to its size, the hypergiant emits very powerful streams of ions similar to solar wind. This makes it impossible for life to exist on bodies near it.
The lifespan of R136a1, like other stars with a mass of 150 solar masses or more, is quite short. After depleting the supply of hydrogen in the core, these cosmic objects explode, forming hypernovae. The power of such an explosion exceeds the power of a supernova by more than 10 times. This produces huge bursts of gamma radiation. It is believed that it was the explosion of one of these hypernovae near the solar system that caused the extinction of life on Earth about 450 million years ago. The “death” of the heaviest star in the Universe, according to astronomers’ calculations, will not bring any harm to our planet.
The largest star in our galaxy
We figured out the largest known star in the Universe. But it is far from Earth and without the help of good optics it cannot be detected in the night sky. There are giants in our galaxy too. Topping their list is Eta Carinae. This unusual object is a system of two objects rotating around a common center of gravity.
The largest star in the Milky Way is located in the constellation Carina, which can be observed in the southern hemisphere of the starry sky. Light from it reaches the Earth in 7500 years.
The Eta Carinae system consists of two objects - the blue hypergiant Eta Carinae A and the blue star η Car B. The main component of the system is a variable luminary, has a mass of 150 Suns and a radius of about 800 solar. At the same time, the star is rapidly losing stellar matter and will soon become a supernova. η Car B is 30 times heavier and 20 times larger than the Sun. The temperature of its surface exceeds 37 * 10 3 K. Unlike the main component, this component of the Eta Carinae system has been little studied.
The components of the Eta Carinae system vary greatly in mass and size. The main one is the hypergiant Eta Carinae A, a huge variable star. It is 150 times heavier and almost 800 times heavier. This is one of the most unstable bodies in outer space. It quickly loses its substance, which will soon lead to a supernova explosion.
Component B, or η Car B, belongs to the spectral class O. Its mass is equal to 30 solar masses, and its radius is 20 times that of the Sun. η Car B, like a satellite, rotates around the main component of the system.
Due to the variable luminosity of Eta Carinae A, the brightness of the entire system is constantly changing. The last observed peak of luminosity occurred in the 40s of the 19th century. At that time, the largest star in the Milky Way shone 50 million times brighter than the Sun. Then a pseudo-supernova explosion occurred, which reduced the brightness of Eta Carinae by 10 times. It remains at this level today. The second component of the system is several hundred thousand times brighter than the Sun.
The explosion of Eta Carinae A will not harm all living beings on the surface. However, this event could disable satellites in low-Earth orbit and also affect the thickness of the ozone layer of the atmosphere.
Top 10 giants
There are many objects larger than the Sun in the Metagalaxy. We will list only the 10 largest stars in the Universe:
- VY Canis Majoris is a hypergiant constellation of the same name, located 1170 parsecs from the Solar System. The radius is 2000 solar. It is 270,000 times brighter than our star.
- VV Cephei is a two-component star system in the constellation Cepheus. It is 5 thousand light years away from Earth. Belongs to the group of red hypergiants. 1,700 times larger and 200,000 times brighter than the Sun.
- MY Cephei is another large star in the Cepheus constellation. Belongs to the group of red hypergiants. Radius – 1600 solar.
- V838 Monoceros - 20,000 light years away from Earth. Has variable luminosity. The size varies from 1200 to 1900 solar radii according to data from different groups of researchers.
- WOH G64 is a red supergiant from the constellation Pisces. Light from it reaches the solar system in 163,000 years. Its size is 1540-2200 radii of our star, and its luminosity is 500,000 Suns.
- V354 Cephei is 690-1250 times larger than the Sun and 400,000 times brighter.
- KY Cygni - is located in the constellation of the same name, located 5 thousand light years from Earth. Its radius is 1450 solar.
- KW Sagittarius is a red supergiant, 1460 times larger than our star.
- RW Cepheus - its dimensions are from 1250 to 1650 solar radii.
