Top 10 biggest stars. What is the largest star in the Universe

Science

Of course, the oceans are vast and the mountains incredibly high. Moreover, the 7 billion people who call the Earth home is also incredible large number. But, living in this world with a diameter of 12,742 kilometers, it is easy to forget that this is, in essence, a trifle for such a thing as space. When we look into the night sky, we realize that we are just a grain of sand in a vast, infinite Universe. We invite you to learn about the largest objects in space; the size of some of them is difficult for us to imagine.

1) Jupiter

The largest planet in the solar system (142,984 kilometers in diameter)

Jupiter is our largest planet star system. Ancient astronomers named this planet in honor of the father of the Roman gods, Jupiter. Jupiter is the fifth planet from the Sun. The planet's atmosphere is 84 percent hydrogen and 15 percent helium. Everything else is acetylene, ammonia, ethane, methane, phosphine and water vapor.

The mass of Jupiter is 318 times greater than the mass of the Earth, and its diameter is 11 times greater. The mass of this giant is 70 percent of the mass of all planets solar system. Jupiter's volume is large enough to accommodate 1,300 Earth-like planets. Jupiter has 63 known moons, but most of them are incredibly small and fuzzy.

2) Sun

The largest object in the Solar System (1,391,980 kilometers in diameter)

Our Sun is a yellow dwarf star, the largest object in the star system in which we exist. The Sun contains 99.8 percent of the mass of this entire system, with Jupiter accounting for most of the rest. The Sun currently consists of 70 percent hydrogen and 28 percent helium, with the remaining substances making up only 2 percent of its mass.

Over time, hydrogen in the Sun's core turns into helium. Conditions in the Sun's core, which makes up 25 percent of its diameter, are extreme. The temperature is 15.6 million Kelvin and the pressure is 250 billion atmospheres. The energy of the Sun is achieved through nuclear fusion reactions. Every second, approximately 700,000,000 tons of hydrogen are converted into 695,000,000 tons of helium and 5,000,000 tons of energy in the form of gamma rays.

3) Our Solar System

1510 12 kilometers in diameter*

Our solar system contains just one star, which is the central object, and nine major planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto, as well as many moons, millions of rocky asteroids and billions of icy comets.

4) Star VY Canis Majoris

The largest star in the Universe (3 billion kilometers in diameter)

VY Canis Major- the largest known star and one of the most bright stars in the sky. This is a red hypergiant, which is located in the constellation Canis Major. The radius of this star is approximately 1800-2200 times greater than the radius of our Sun, its diameter is approximately 3 billion kilometers.

If this star were placed in our solar system, it would block the orbit of Saturn. Some astronomers believe that VY is actually smaller—about 600 times the size of the Sun—and would therefore only reach the orbit of Mars.

5) Huge deposits of water

Astronomers have discovered the largest and most massive reserves of water ever found in the Universe. The giant cloud, which is about 12 billion years old, contains 140 trillion times more water than all of Earth's oceans combined.

A cloud of gaseous water surrounds a supermassive black hole, which is located 12 billion light years from Earth. This discovery shows that water has dominated the universe for almost all of its existence, the researchers said.

6) Extremely large and massive black holes

21 billion solar masses

Supermassive black holes are the largest black holes in the galaxy, with a mass of hundreds or even thousands of millions of solar masses. Most, and perhaps all, galaxies, including the Milky Way, are believed to contain supermassive black holes at their centers.

One such monster, which has a mass 21 million times greater than the mass of the Sun, is an egg-shaped funnel of stars in the galaxy NGC 4889, the brightest galaxy in a sprawling cloud of thousands of galaxies. The hole is located approximately 336 million light years away in the constellation Coma Berenices. This black hole is so huge that it is 12 times larger in diameter than our Solar System.

7) Milky Way

100-120 thousand light years in diameter

The Milky Way is a rugged spiral galaxy that contains 200-400 billion stars. Each of these stars has many planets orbiting it.

According to some estimates, 10 billion planets are in the habitable zone, revolving around their parent stars, that is, in zones where there are all the conditions for the emergence of life similar to Earth.

8) El Gordo

The largest cluster of galaxies (210 15 solar masses)*

El Gordo is located more than 7 billion light years from Earth, so what we see today is just its early stages. According to researchers who have studied this galaxy cluster, it is the largest, hottest and emits more radiation than any other known cluster at the same distance or further away.

The central galaxy at the center of El Gordo is incredibly bright and has an unusual blue glow. The study authors suggest that this extreme galaxy is the result of a collision and merger of two galaxies.

Using the Spitzer Space Telescope and optical images, scientists estimate that 1 percent of the cluster's total mass is stars, and the rest is hot gas that fills outer space between the stars. This ratio of stars to gas is similar to that in other massive clusters.

9) Our Universe

Size – 156 billion light years

Of course, no one has ever been able to name the exact dimensions of the Universe, but, according to some estimates, its diameter is 1.5 * 10 24 kilometers. It’s generally difficult for us to imagine that there is an end somewhere, because the Universe includes incredibly gigantic objects:

Diameter of the Earth: 1.27*10 4 km

Diameter of the Sun: 1.39*10 6 km

Solar system: 2.99 * 10 10 km or 0.0032 light. l.

Distance from the Sun to the nearest star: 4.5 sv. l.

Milky Way: 1.51*10 18 km or 160,000 St. l.

Local group of galaxies: 3.1 * 10 19 km or 6.5 million light years. l.

Local supercluster: 1.2*10 21 km or 130 million light. l.

10) Multiverse

You can try to imagine not one, but many Universes that exist at the same time. A multiverse (or multiple universe) is a feasible collection of many possible universes, including our own, which together contain everything that exists or can exist: the integrity of space, time, material matter and energy, as well as the physical laws and constants that make it all describe.

However, the existence of other Universes besides ours has not been proven, so it is very likely that our Universe is one of a kind.

An illustration of the star R136a1, the most massive star known to date. Credit: Sephirohq / Wikipedia.

Look at the night sky - it is filled with stars. However, only a microscopic part of them is visible to the naked eye. In fact, scientists estimate that there are 10,000 billion galaxies in the visible Universe, each with more than a hundred billion stars. And this is no less than 10 24 stars. These spectacular thermal plants come in a variety of colors and sizes - and many of them make our Sun look tiny in comparison. However, which star is a true cosmic giant? First, we need to define the concept of a giant star: should it have the greatest radius or the greatest mass?

Today, the star with the largest radius is the star UY Scuti (Scuti), a variable red supergiant in the constellation Scutum. It is more than 9,500 light years away from us, and consists mostly of hydrogen and helium, as well as a number of other heavier elements. By chemical composition UY Scuti resembles our Sun, but has a radius 1708 (± 192) times greater than that of our star. That is almost 1,200,000,000 km, making its circumference more than 7.5 billion kilometers. To make it easier to understand such dimensions, you can imagine a plane that would take 950 years to fly around UY Scuti - and even if the plane could move at the speed of light, its journey would last 6 hours and 55 minutes.

If we place UY Scutum in the place of our Sun, then its surface will pass somewhere between the orbits of Jupiter and Saturn - it goes without saying that the Earth will be engulfed in this case. Considering the huge size and mass from 20 to 40 solar masses, it can be calculated that the density of the UY Shield is only 7 × 10 -6 kg/m 3. In other words, it is more than a billion times less dense than water. In fact, if we could place this star in a pool, then theoretically it would float. Being more than a million times less dense than earth's atmosphere UY Shield, similar balloon, would fly in the air.

But if these crazy facts didn't surprise you, then let's move on to the heaviest star. The heavyweight star R136a1 is located in the Large Magellanic Cloud, approximately 165,000 light-years away. This star is only 35 times larger than our Sun, but it is 265 times heavier - this is truly amazing considering the fact that it has already lost 55 solar masses in its 1.6 million years of life.

R136a1 is a highly unstable Wolf-Rayet star. It appears as a blue ball with a fuzzy surface that constantly generates extremely powerful stellar winds. These winds move at speeds of up to 2600 km/s. Because of this high activity, R136a1 loses 3.21 x 10 18 kg/s of its mass - that's about one Earth every 22 days. These types of stars shine brightly and die quickly. R136a1 emits nine million times more energy than our Sun. Its brightness is 94,000 times greater than the brightness of the Sun. In fact, it is the brightest star ever found. The temperature on its surface is more than 53,000 Kelvin, and it has only two million years to live after which it will explode as a supernova.

Of course, compared to such giants, our Sun appears to be a dwarf, but over time it will also increase in size. In about seven and a half billion years, it will reach its largest size and become a red giant.

Not only astronomers and romantics love to look at the sky. We all look up to the stars from time to time and admire their eternal beauty. That’s why each of us is at least sometimes interested in which star in the sky is the brightest.

The Greek scientist Hipparchus first asked this question, and he proposed his classification 22 centuries ago! He divided the stars into six groups, where the first magnitude stars were the brightest he could observe, and the sixth magnitude were those barely visible to the naked eye.

Needless to say that we are talking about relative brightness, and not about the actual ability to glow? Indeed, in addition to the amount of light produced, the brightness of a star observed from Earth is affected by the distance from this star to the observation site. It seems to us that the brightest star in the sky is the Sun, because it is closest to us. In fact, it is not at all a bright and very small star.

Nowadays, approximately the same system for distinguishing stars by brightness is used, only improved. Vega was taken as the reference point, and the brightness of the remaining stars is measured from its indicator. The brightest stars have a negative index.

So, we will consider exactly those stars that are recognized as the brightest according to the improved Hipparchus scale

10 Betelgeuse (α Orionis)

The red giant, with 17 times the mass of our Sun, rounds out the top 10 brightest night stars.

This is one of the most mysterious stars in the Universe, because it is capable of changing its size, while its density remains unchanged. The color and brightness of the giant varies at different points.

Scientists expect Betelgeuse to explode in the future, but given that the star is located at a huge distance from the Earth (according to some scientists - 500, according to others - 640 light years), this should not affect us. However, for several months the star can be seen in the sky even during the day.

9 Achernar (α Eridani)

A favorite of science fiction writers, a blue star with a mass 8 times greater than that of the Sun looks very impressive and unusual. The star Achernar is flattened so that it resembles a rugby ball or a tasty torpedo melon, and the reason for this is a fantastic rotation speed of more than 300 km per second, approaching the so-called separation speed, at which the centrifugal force becomes identical to the force of gravity.

8 Procyon (α Canis Minor)

One of the two “dog stars” is similar to Sirius in that it is the brightest star in the constellation Canis Minor (and Sirius is the brightest star in Canis Major), and in that it is also double.

Procyon A is a pale yellow star about the size of the Sun. It is gradually expanding, and in 10 million years it will become an orange or red giant. According to scientists, the process is already underway, as evidenced by the unprecedented brightness of the star - it is more than 7 times brighter than the sun, although similar in size and spectrum.

Procyon B, its companion, a dim white dwarf, is about the same distance from Procyon A as Uranus is from the Sun.

And there were some mysteries here. Ten years ago, a long-term study of the star was undertaken using an orbiting telescope. Astronomers were eager to get confirmation of their hypotheses. However, the hypotheses were not confirmed, and now scientists are trying to explain what is happening on Procyon in some other way.

Continuing the “dog” theme – the name of the star means “in front of the dog”; this means that Procyon appears in the sky before Sirius.

7 Rigel (β Orionis)

In seventh place in terms of relative (observed by us) brightness is one of the most powerful stars in the Universe with an absolute magnitude of -7, that is, the brightest of the stars located more or less nearby.

It is located 870 light years away, so less bright but closer stars appear brighter to us. Meanwhile, Rigel is 130 thousand times brighter than the Sun and 74 times larger in diameter!

The temperature on Rigel is so high that if something were to be at the same distance from it as the Earth is relative to the Sun, that object would immediately turn into a stellar wind!

Rigel has two companion stars, almost invisible in brightest radiance blue-white supergiant.

6 Chapel (α Auriga)

Capella ranks third among the brightest stars in the Northern Hemisphere. Of the stars of the first magnitude (the famous Polaris is only of the second magnitude), Capella is located closest to the North Pole.

This is also a double star, and the weaker of the pair is already becoming red, and the brighter is still white, although the hydrogen in its body has obviously already turned into helium, but has not yet ignited.

The name of the star means Goat, because the Greeks identified it with the goat Amalthea, who suckled Zeus.

5 Vega (α Lyrae)

The brightest of the Sun's neighbors can be observed throughout the entire Northern Hemisphere and almost the entire Southern Hemisphere, except Antarctica.

Vega is beloved by astronomers for being the second most studied star after the Sun. Although there is still a lot of mystery in this “most studied” star. What can we do, the stars are in no hurry to reveal their secrets to us!

Vega's rotation speed is very high (it rotates 137 times faster than the Sun, almost as fast as Achernar), so the star's temperature (and therefore its color) differs at the equator and at the poles. Now we see Vega from the pole, so it appears pale blue to us.

Around Vega there is a large cloud of dust, the origin of which is controversial among scientists. The question of whether Vega has a planetary system is also debatable.

4 The brightest star in the Northern Hemisphere is Arcturus (α Bootes)

In fourth place is the brightest star of the Northern Hemisphere - Arcturus, which in Russia can be observed anywhere throughout the year. However, it is also visible in the Southern Hemisphere.

Arcturus is many times brighter than the Sun: if we take into account only the range perceived by the human eye, then more than a hundred times, but if we take the intensity of the glow as a whole, then 180 times! This is an orange giant with an atypical spectrum. Someday our Sun will reach the same stage that Arcturus is at now.

According to one version, Arcturus and its neighboring stars (the so-called Arcturus Stream) were once captured Milky Way. That is, all these stars are of extragalactic origin.

3 Toliman (α Centauri)

This is a double, or rather, even a triple star, but we see two of them as one, and the third, dimmer one, which is called Proxima, as if separately. However, in fact, all these stars are not very bright, but are located not far from us.

Since Toliman is somewhat similar to the Sun, astronomers have long and persistently been looking for a planet near it, similar to Earth and located at a distance that makes life on it possible. In addition, this system, as already mentioned, is located relatively close, so the first interstellar flight will probably be there.

Therefore, the love of science fiction writers for Alpha Centauri is understandable. Stanislav Lem (creator of the famous Solaris), Asimov, Heinlein devoted pages of their books to this system; The action of the acclaimed film “Avatar” also takes place in the Alpha Centauri system.

2 Canopus (α Carinae) is the brightest star in the Southern Hemisphere

In absolute terms of luminosity, Canopus is much brighter than Sirius, which, in turn, is much closer to Earth, so that objectively it is the brightest night star, but from a distance (it is located at a distance of 310 light years) it seems dimmer to us than Sirius.

Canopus is a yellowish supergiant whose mass is 9 times the mass of the Sun, and it glows 14 thousand times more intensely!

Unfortunately, it is impossible to see this star in Russia: it is not visible north of Athens.

But in the Southern Hemisphere, Canopus was used to determine their location in navigation. In the same capacity, Alpha Carinae is used by our astronauts.

1 The brightest star in our starry sky is Sirius (α Canis Majoris)

The famous “dog star” (it was not for nothing that J. Rowling called her hero, who turned into a dog, that way), the appearance of which in the sky meant the beginning of vacation for ancient schoolchildren (this word means “dog days”) is one of the closest to the solar system and therefore perfectly visible from almost anywhere on Earth, except the Far North.

It is now believed that Sirius is a double star. Sirius A is twice as large as the Sun, and Sirius B is smaller. Although millions of years ago, apparently, it was the other way around.

Many peoples have left various legends associated with this star. The Egyptians considered Sirius to be the star of Isis, the Greeks - the dog of Orion taken to heaven, the Romans called him Canicula (“little dog”), in ancient Russian this star was called Psitsa.

The ancients described Sirius as a red star, while we observe a bluish glow. Scientists can only explain this by assuming that all ancient descriptions were compiled by people who saw Sirius low above the horizon, when its color was distorted by water vapor.

Be that as it may, now Sirius is the brightest star in our sky, which can be seen with the naked eye even during the day!

In fact, this question is not as simple as it seems. Determining the exact sizes of stars is very difficult; this is calculated based on a lot of indirect data, because we cannot see their disks directly. Direct observation of the stellar disk has so far been carried out only for some large and nearby supergiants, and there are millions of stars in the sky. Therefore, determining which is the largest star in the Universe is not so simple - you have to rely mainly on calculated data.

In addition, for some stars the boundary between the surface and the huge atmosphere is very blurred, and it is difficult to understand where one ends and the other begins. But this is an error not of some hundreds, but of millions of kilometers.

Many stars do not have a strictly defined diameter; they pulsate and become larger and smaller. And they can change their diameter very significantly.

In addition, science does not stand still. More and more accurate measurements are being made, distances and other parameters are being clarified, and some stars suddenly turn out to be much more interesting than they seemed. This also applies to sizes. Therefore, we will consider several candidates that are among the largest stars in the Universe. Note that they are all not very far away by cosmic standards, and they are also the largest stars in the Galaxy.

A red hypergiant that claims to be the most big stars in the Universe. Alas, this is not true, but it is very close. In size it is in third place.

VV Cephei - that is, double, and the giant in this system is component A, which will be discussed. The second component is an unremarkable blue star, 8 times larger than the Sun. But the red hypergiant is also a pulsating star, with a period of 150 days. Its size can vary from 1050 to 1900 times the diameter of the Sun, and at its maximum it shines 575,000 times brighter than our star!

This star is located 5000 light years away from us, and at the same time it has a brightness of 5.18 m in the sky, that is, with a clear sky and good vision, it can be found, and even easily with binoculars.

UY Shield

This red hypergiant is also striking in its size. Some sites mention it as the largest star in the Universe. It belongs to semi-regular variables and pulsates, so the diameter can vary - from 1708 to 1900 solar diameters. Just imagine a star 1900 times larger than our Sun! If you place it at the center of the solar system, then all the planets, up to Jupiter, will be inside it.

Sun, Sirius, Pollux, Arcturus, against the background of UY Scutum. It is probably the largest star in the Universe.

In numbers, the diameter of this one of the largest stars in space is 2.4 billion kilometers, or 15.9 astronomical units. 5 billion suns could fit inside it. It shines 340,000 times stronger than the Sun, although the surface temperature is much lower - due to its larger area.

At its peak brightness, UY Scuti is visible as a faint reddish star with a brightness of 11.2 m, that is, it can be seen with a small telescope, but is not visible to the naked eye. The fact is that the distance to this large star is 9500 light years - we would not have seen another one at all. In addition, there are clouds of dust between us - if they were not there, UY Scuti would be one of the brightest stars in our sky, despite the enormous distance to it.

UY Scuti is a huge star. It can be compared with the previous candidate - VV Cepheus. At maximum they are approximately the same, and it is not even clear which one is larger. However, there is definitely an even bigger star!

VY Canis Majoris

The diameter of VY, however, according to some data, is estimated at 1800-2100 solar, that is, it is a clear record holder among all other red hypergiants. If it were in the center of the solar system, it would swallow all the planets, along with Saturn. The previous candidates for the title of the largest stars in the Universe would also fit completely into it.

It only takes 14.5 seconds for light to circle our Sun completely. To go around VY Canis Majoris, the light would have to travel 8.5 hours! If you decided to fly around the surface in a fighter jet at a speed of 4500 km/h, such a non-stop journey would take 220 years.

Comparison of the sizes of the Sun and VY Canis Majoris.

This star still raises a lot of questions, since its exact size is difficult to establish due to the blurry corona, which has a much lower density than the solar one. And the star itself has a density thousands of times less than the density of the air we breathe.

In addition, VY Canis Majoris is losing its matter and has formed a noticeable nebula around itself. This nebula may now contain even more matter than the star itself. Moreover, it is unstable, and in the next 100 thousand years will explode hypernova. Fortunately, it is 3900 light years away, and this terrible explosion does not threaten the Earth.

This star can be found in the sky with binoculars or a small telescope - its brightness varies from 6.5 to 9.6 m.

Which star is the largest in the Universe?

We looked at several of the largest stars in the Universe known to scientists today. Their sizes are amazing. All of them are candidates for this title, but the data is constantly changing - science does not stand still. According to some data, UY Scuti can also “swell” to 2200 solar diameters, that is, become even larger than VY Canis Majoris. On the other hand, there is too much disagreement about the size of VY Canis Majoris. So these two stars are almost equal candidates for the title of the largest stars in the Universe.

Which of them will actually be larger will be shown by further research and clarification. While the majority is inclined in favor of UY Scuti, and you can safely call this star the largest in the Universe, it will be difficult to refute this statement.

Of course, it is not too correct to talk about the entire Universe. Perhaps this is the largest star in our Milky Way galaxy known to scientists today. But since even larger ones have not yet been discovered, it is still the largest in the Universe.

The Sun is not the largest star in the Universe. Compared to other stars, it can even be called small. But on the scale of our planet, the Sun is truly huge. Its diameter is 1.39 million km, it contains 99.86% of all matter in the Solar System, and inside the star you can place a million planets like our Earth.

The one and only thing for the inhabitants of the Earth, the Sun is just one of the billions of billions of stars located in our Milky Way galaxy, and beyond it - in the endless Universe. Some of these stars are truly huge: they are clearly visible in the electromagnetic spectrum and have such a significant gravitational effect on nearby celestial bodies that we can detect them even if they are millions of light years away from our planet. Their sizes are so large that a person is simply unable to imagine such a gigantic object, so they are measured not in kilometers, but in solar radii and solar mass. One solar radius is 696,342 km, and one solar mass is approximately 2,000,000,000,000,000,000,000,000,000,000 kg.

Stars that stand out significantly from others due to their mass and size are classified as hypergiants. Among the many hypergiants recorded in the vast expanses of the universe, three of them can be particularly highlighted.

R136a1

The largest star will not always be the heaviest, and conversely, the heaviest star does not have to be the largest. This is easily proven by the star under beautiful name R136a1. Located in the Large Magellanic Cloud at a distance of 165,000 light years from Earth, its mass is 265 solar masses, which is an absolute record for at the moment, while its radius is “only” 31 solar radii. Huge reserves of fuel inside this hypergiant and extremely high density substances allow R136a1 to emit 10 million times more light than the Sun, making it the brightest and most powerful star discovered to date. Scientists suggest that at the beginning of its life this star could reach 320 solar masses, however, stellar matter in the atmosphere of R136a1 accelerates more than the second escape velocity and overcomes the gravity of a given celestial body, which generates a strong stellar wind, i.e. the outflow of stellar matter into interstellar space with a rapid loss of its mass.

UY Scuti will not amaze you with its mass, which is 10 solar radii, but you will be surprised by its colossal size - about 1500 solar radii. The distance to UY Scuti is 9500 light years, and at such a distance it is difficult to say the exact radius of the star, but astronomers suggest that during pulsations it can increase to 2000 solar radii! If such a giant were placed in the center of the solar system, it would absorb all of space, including the orbit of Jupiter along with the planet itself. The volume of this hypergiant is 5 billion times greater than the volume of the Sun.

UY Scutum in the constellation Scutum |

UY Scuti is located at a distance of almost ten thousand light years from the Solar System, but due to the fact that the star is one of the brightest among those discovered, it can be easily seen from Earth with a regular amateur telescope, and in particularly favorable conditions with the naked eye. By the way, if UY Scuti were not surrounded by a large cloud of dust, then this star would be the fifth brightest object in the night sky, whereas now it is the eleventh.

NML Swan

The star NML Cygni is a real record holder with a radius equal to 1650 solar radii. During pulsations of a star, the radius can reach about 2700 solar radii! If you place this hypergiant at the center of the solar system, its photosphere will extend far beyond the orbit of Jupiter, covering half the distance to Saturn.

Photo of the group of stars Cygnus OB2 | source

The star NML Cygnus, located in the constellation Cygnus at a distance of 5300 light years from Earth, is the largest star currently known to astronomy. However, we can say with confidence that further space exploration will bring new discoveries and records.