Top 5 biggest stars. The largest stars in the Universe - list, size, comparison, video

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

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

Moreover, science does not stand still. More and more accurate measurements are being made, distances and other parameters are being refined, and some stars are unexpectedly much more interesting than they seemed. This also applies to sizes. Therefore, we will consider several candidates that belong to the largest stars in the Universe. Note that they are all not so far away in cosmic terms, and they are also the most big stars in the Galaxy.

A red hypergiant claiming to be herself big star in the Universe. Alas, this is not so, but very close. In terms of size, it is in third place.

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

This star is 5,000 light years away from us, and at the same time in the sky it has a brightness of 5.18 m, that is, with a clear sky and good vision, it can be found, and even with binoculars it is generally easy.

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 in the center Solar system, then all the planets, up to Jupiter, will be inside it.

Sun, Sirius, Pollux, Arcturus, against the background of the UY Shield. 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. Inside it could fit 5 billion suns. It shines 340,000 times stronger than the Sun, although the surface temperature is much lower - due to its larger area.

At the peak of brightness UY of the Shield, it is visible as a faint reddish star with a brightness of 11.2 m, that is, it can be seen through a small telescope, but it 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 on it at all. In addition, there are dust clouds between us - if they were not there, UY Shield would be one of the brightest stars in our sky, despite the great distance to it.

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

VY Big Dog

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

Light takes only 14.5 seconds to circle our Sun completely. To go around VY Big Dog, the light would have to fly for 8.5 hours! If you were to make such a flyby along the surface in a fighter jet, at a speed of 4500 km / h, then such a non-stop journey would take 220 years.

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

This star still raises a lot of questions, since its exact size is difficult to establish due to the diffuse 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 Major is losing its substance and has formed a noticeable nebula around itself. This nebula may now have even more matter than the star itself. In addition, it is unstable, and will explode into a hypernova in the next 100 thousand years. Fortunately, it is 3,900 light years away, and the Earth is terrible explosion does not threaten.

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

What is the largest star in the universe?

We looked at some 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 reports, UY Shield can also "swell" up to 2200 solar diameters, that is, it becomes even larger than VY Canis Major. On the other hand, there is too much controversy about the VY size of Canis Major. So these two stars are practically equal candidates for the title of the largest stars in the Universe.

Which of them turns out to be more in fact, will be shown by further research and clarifications. While the majority is inclined in favor of UY Shield, and you can safely call this star the largest in the Universe, it will be difficult to refute this statement.

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

In contact with

Seemingly inconspicuous Shield UY

In terms of stars, modern astrophysics seems to be reliving its infancy. Observing stars gives more questions than answers. Therefore, when asking about which star is the largest in the Universe, you need to be immediately ready for answering questions. Are you asking about the largest star known to science, or what limits science limits a star to? As is usually the case, in both cases, you will not get a definite answer. The most likely candidate for the largest star shares the palm with his “neighbors” on an equal footing. As to how much smaller he can be than the real "king of the star" also remains open.

Comparison of the sizes of the Sun and the star UY Shield. The Sun is an almost invisible pixel to the left of the UY Shield.

The supergiant UY Shield, with some reservations, can be called the largest star observed today. Why "with a reservation" will be discussed below. Shield UY is 9,500 light-years distant and is seen as a faint variable asterisk visible through a small telescope. According to astronomers, its radius exceeds 1700 solar radii, and during the pulsation period this size can increase to as much as 2000.

It turns out, to place such a star in the place of the Sun, the current orbits of the terrestrial planet would be in the bowels of the supergiant, and the boundaries of its photosphere would at times rest against the orbit. If we imagine our Earth as a grain of buckwheat, and the Sun as a watermelon, then the diameter of the UY Shield will be comparable to the height of the Ostankino TV tower.

It will take as much as 7-8 hours to fly around such a star at the speed of light. Let's remember that the light emitted by the Sun reaches our planet in just 8 minutes. If you fly at the same speed with which it makes one revolution around the Earth in an hour and a half, then the flight around the UY Shield will last about 36 years. Now let's imagine these scales, given that the ISS flies 20 times faster than a bullet and ten times faster than passenger airliners.

Mass and luminosity of the UY Shield

It is worth noting that such a monstrous size of the UY Shield is completely incomparable with its other parameters. This star is "only" 7-10 times more massive than the Sun. It turns out, average density this supergiant is almost a million times lower than the density of the air that surrounds us! For comparison, the density of the Sun is one and a half times higher than the density of water, and a grain of matter even "weighs" millions of tons. Roughly speaking, the averaged matter of such a star is similar in density to the layer of the atmosphere located at an altitude of about one hundred kilometers above sea level. This layer, also called the Karman line, is the conditional border between the earth's atmosphere and space. It turns out that the density of the UY Shield only slightly falls short of the cosmic vacuum!

Also UY Shield is not the brightest. With its own luminosity of 340,000 solar, it is ten times dimmer than the most bright stars... A good example is the star R136, which, being the most massive star known today (265 solar masses), is nearly nine million times brighter than the Sun. Moreover, the star is only 36 times larger than the Sun. It turns out that R136 is 25 times brighter and about as many times more massive than the UY Shield, despite the fact that it is 50 times smaller than the giant.

Physical parameters of the UY Shield

In general, UY Shield is a pulsating variable red supergiant spectral class M4Ia. That is, on the Hertzsprung-Russell spectrum-luminosity diagram, the UY Shield is located in the upper right corner.

At the moment, the star is approaching the final stages of its evolution. Like all supergiants, it began to actively burn helium and some other heavier elements. According to modern models, after a few millions of years, the UY of the Shield will successively transform into a yellow supergiant, then into a bright blue variable or a Wolf-Rayet star. The final stages of its evolution will be a supernova explosion, during which the star will throw off its shell, most likely leaving behind a neutron star.

Already, the UY Shield is showing its activity in the form of semi-regular variability with an approximate pulsation period of 740 days. Considering that a star can change its radius from 1700 to 2000 solar radii, the speed of its expansion and contraction is comparable to the speed spaceships! The loss of its mass amounts to an impressive rate of 58 million solar masses per year (or 19 Earth masses per year). This is almost one and a half Earth masses per month. So, being millions of years ago on the main sequence, the UY of the Shield could have a mass from 25 to 40 solar masses.

Giants among the stars

Returning to the disclaimer mentioned above, we note that the primacy of UY Shield as the largest known star cannot be called unambiguous. The fact is that astronomers still cannot determine the distance to most stars with a sufficient degree of accuracy, and therefore estimate their sizes. In addition, large stars are usually very unstable (remember the pulsation of the UY Shield). Likewise, they have a rather blurry structure. They can have a rather extended atmosphere, opaque gas and dust envelopes, disks, or a large companion star (for example, VV Cephei, see below). It is impossible to say exactly where the border of such stars lies. In the end, the well-established concept of the boundary of stars as the radius of their photosphere is already extremely conditional.

Therefore, this number can include about a dozen stars, which include NML Cygnus, VV Cepheus A, VY Canis Major, WOH G64 and some others. All these stars are located in the vicinity of our galaxy (counting its satellites) and are in many ways similar to each other. All of them are red supergiants or hypergiants (see below for the difference between super- and hypergiants). Each of them in a matter of millions, if not thousands of years, will turn into a supernova. They are also similar in size, ranging from 1400-2000 solar.

Each of these stars has its own peculiarity. So for UY Shield, this feature is the previously mentioned variability. WOH G64 has a toroidal gas and dust shell. The double eclipsing variable star VV Cephei is extremely interesting. It is a close system of two stars, consisting of a red hypergiant VV Cephei A and a blue main sequence star VV Cephei B. The cents of these stars are located some 17-34 apart from each other. Considering that the VV radius of Cepheus B can reach 9 AU. (1900 solar radii), the stars are located at an "arm's length" from each other. Their tandem is so close that whole pieces of the hypergiant are flowing at high speeds to the "little neighbor", which is almost 200 times smaller than it.

Looking for a leader

Under such conditions, estimating the size of stars is already problematic. How can you talk about the size of a star if its atmosphere flows into another star, or smoothly transforms into a disk of gas and dust? This is despite the fact that the star itself consists of a very rarefied gas.

Moreover, all the largest stars are extremely unstable and short-lived. Such stars can live for a few millions, or even hundreds of thousands of years. Therefore, observing a giant star in another galaxy, one can be sure that a neutron star is pulsating in its place or a black hole surrounded by supernova remnants is curving space. Even if such a star is thousands of light years away, one cannot be completely sure that it still exists or remains the same giant.

Add imperfection to this modern methods determining the distance to the stars and a number of unspecified problems. It turns out that even among the ten largest known stars, it is impossible to single out a certain leader and arrange them in ascending order of size. In this case, Shield's UY was cited as the most likely candidate for leadership among the Big Ten. This does not mean at all that his leadership is undeniable and that, for example, NML Swan or VY Big Dog cannot be larger than her. Therefore, different sources can answer the question about the largest known star in different ways. This speaks rather not of their incompetence, but of the fact that science cannot give unambiguous answers even to such direct questions.

The largest in the universe

If science does not undertake to single out the largest among the open stars, how can we talk about which star is the largest in the Universe? According to scientists, the number of stars, even within the boundaries of the observable Universe, is ten times the number of grains of sand on all the beaches of the world. Of course, even the most powerful modern telescopes can see an unimaginably small fraction of them. The fact that the largest stars can stand out for their luminosity will not help in the search for a "star leader". Whatever their brightness, it will fade when observed distant galaxies... Moreover, as noted earlier, the brightest stars are not the largest (for example, R136).

Also remember that observing a large star in distant galaxy, we will actually see her "ghost". Therefore, it is not easy to find the largest star in the Universe, its search will be simply pointless.

Hypergiants

If the largest star is practically impossible to find, maybe it is worth developing it theoretically? That is, to find a certain limit after which the existence of a star can no longer be a star. However, even here modern science faces a problem. The current theoretical model of evolution and stellar physics does not explain much of what actually exists and is observed through telescopes. Hypergiants are an example of this.

Astronomers have repeatedly had to raise the stellar mass limit. This limit was first introduced in 1924 by the English astrophysicist Arthur Eddington. Having received the cubic dependence of the luminosity of stars on their mass. Eddington realized that a star cannot accumulate mass indefinitely. The brightness increases faster than the mass, and sooner or later this will lead to a violation of the hydrostatic equilibrium. The light pressure of increasing brightness will literally blow off the outer layers of the star. The limit calculated by Eddington was 65 solar masses. Subsequently, astrophysicists refined his calculations, adding unaccounted for components and using powerful computers. So the current theoretical mass limit for stars is 150 solar masses. Now let's remember that the mass of R136a1 is 265 solar masses, which is almost twice the theoretical limit!

R136a1 is the most massive star known today. In addition to it, several more stars have significant masses, the number of which in our galaxy can be counted on one hand. Such stars were called hypergiants. Note that R136a1 is much smaller than the stars, which, it would seem, should be lower in class - for example, the supergiant UY Shield. This is because he calls hypergiants not the largest, but the most massive stars. For such stars, a separate class was created on the spectrum-luminosity diagram (O), located above the class of supergiants (Ia). The exact initial mass of the hypergiant has not been established, but, as a rule, their mass exceeds 100 solar. None of the biggest stars in the Big Ten fall within these limits.

Theoretical impasse

Modern science cannot explain the nature of the existence of stars, the mass of which exceeds 150 solar masses. This raises the question of how the theoretical limit of the size of stars can be determined if the radius of the star, as opposed to the mass, is itself a vague concept.

Let's take into account the fact that it is not known exactly what the stars of the first generation were, and what they will be in the course of the further evolution of the Universe. Changes in the composition and metallicity of stars can lead to radical changes in their structure. An astrophysicist only has to comprehend the surprises that further observations and theoretical research will present them. It is quite possible that UY Shield may turn out to be a real crumb against the background of a hypothetical "king-star" that shines somewhere or will shine in the most distant corners of our Universe.

>> The largest star in the Universe

UY Shield is the largest star in the Universe: description and characteristics of a star with a photo, location in the constellation, distance from Earth, a list of the largest stars.

It's easy to feel tiny when looking at the night sky. You just need to select an object for comparison. How about a star? Just look into the territory of the constellation Shield and you will find the largest star in our galaxy and the visible Universe - UY Shield.

In 1860, the star was found by German scientists at the Bonn Observatory. But only in 2012 was it possible to conduct a survey in the Very Large Telescope (Atacama Desert). Since its discovery, it is the largest star in size, surpassing Betelgeuse, VY Canis Major and NML Swan.

Of course, there are record holders for brightness and density, but UY Shield has the largest total size with a radius of 1,054,378,000 - 1,321,450,000 miles, which is 1,700 times the solar one.

It seems to people that the Earth is huge. But let's take an 8-inch ball. Then, in scale, the Sun will be 73 feet in diameter, which exceeds the height of the White House. Now let's put UY of the Shield next to it and get a diameter of 125,000 feet.

What happens if you put the UY Shield in a sunny position? The star will dine on the first five planets and go beyond Jupiter's orbital path. But many people think that it can even cross the line of Saturn's orbit.

Well, let's be glad that the star is still not located in the solar system and is 9,500 light years distant.

It is important to emphasize that with the improvement of terrestrial instruments, we are discovering new objects that are distant at great distances. This means that one day we may bump into an even larger star.

It is worth noting that the largest known stars are represented here, since many objects remain outside the field of view. Also, some of the named ones act as variables, which means they are constantly shrinking and expanding. Now you know which is the largest star in space. Let's look at the rest of the top ten the largest stars in the Universe:

List of the largest stars in the universe

The red supergiant VY Canis Major has a radius of 1800-2100 solar, making it the largest in the galaxy. If put in place, it would cover the orbital path. It is 3900 light years distant towards the constellation Canis Major.

It is a red supergiant 1000 times the solar radius. Located 6,000 light years away. Represented by a binary system, where main star accompanied by a small blue.

Mu Cephei

Mu Cephei is a red supergiant whose radius is 1,650 times larger than the sun and 38,000 times brighter.

V 838 Unicorn is a red variable star 20,000 light years distant. It can reach the size of Mu Cephei or VV Cephei A, but the large distance makes it difficult to determine accurately. The range covers 380-1970 solar radii.

A red supergiant that is 1540 times larger than the solar radius. Located in the constellation Dorado.

V354 Cephei

A red supergiant that exceeds the solar radius by 1520 times. It is 9,000 light years distant towards the constellation Cepheus.

KY Swan

1420 times the solar radius, although some estimates put the figure at 2850 times. The star is 5,000 light years away and has not yet been able to get a clear image.

KW Sagittarius

The red supergiant is 1,460 times larger in radius than the Sun. Located 7800 light years away.

RW Cephei

A red supergiant with a radius of 1600 solar. From the position of the Sun, it could reach the orbital path of Jupiter.

A red supergiant with a radius 1000 times that of the Sun. It is the most popular star as it is located fairly close (640 light years) to. At any moment, it can transform into a supernova.

An illustration of the star R136a1 - the most massive known to date. Credit & Copyright: 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 power plants come in a variety of colors and sizes - and in comparison to many of them, our Sun looks just tiny. However, which star is the real space giant? First, we need to define the concept of a giant star: should it have the largest radius or the largest mass?

To date, the star with the largest radius is recognized as the star UY Shield (Scuti) - a variable red supergiant in the constellation of Shield. It is more than 9500 light-years distant from us, and consists mostly of hydrogen and helium, as well as a number of other heavier elements. By chemical composition The UY of the Shield resembles our Sun, but has a radius 1708 (± 192) times larger than that of our star. That is, almost 1,200,000,000 km, resulting in a circumference of over 7.5 billion kilometers. To make it easier to understand such dimensions, one can imagine an airplane that will take 950 years to fly around the UY Shield - and even if the plane can move at the speed of light, its journey will last 6 hours and 55 minutes.

If we place the UY of the Shield 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 in this case will be absorbed. Given the enormous size and mass of 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, this is more than a billion times less than the density of water. Indeed, if we could place this star in the pool, then theoretically it would float. Being more than a million times less dense than the Earth's atmosphere of the UY Shield, like 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 heavy 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 265 times heavier than it - this is really surprising considering the fact that it has already lost 55 solar masses in 1.6 million years of its life.

R136a1 is a highly unstable Wolf-Rayet star. It looks like a blue ball with a fuzzy surface, which constantly forms extremely powerful stellar winds. These winds move at speeds up to 2600 km / s. Due to such high activity, R136a1 loses 3.21 × 10 18 kg / s of its mass - this is approximately one Earth every 22 days. Stars of this type shine brightly and die quickly. R136a1 emits nine million times more energy than our Sun. Its brightness is 94,000 times that 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 left to live, after which it will explode like a supernova.

Of course, against such giants, our Sun seems 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.

Determining the largest star in the Universe, its size and mass has always been difficult for scientists. The angular dimensions of the stars are so small that even the largest telescopes cannot see stars in the form of round disks. Accordingly, the size of the stars, even with the largest telescope, cannot be determined. Scientists have learned to determine the size of the largest stars based on three of the most famous methods:

Observing the eclipse of the Earth's satellite - the Moon, scientists have learned to determine the angular size, and knowing the distance to the object, it is possible to determine its true, linear dimensions;
The size of a star can be determined using special stellar optical interferometers. The principle of operation of these devices is based on the interference of star light, which is reflected by a pair of widely spaced mirrors.
The size of a star can also be calculated theoretically, based on estimates of the total luminosity and temperature of stars according to the Stefan – Boltzmann law. The luminosity of a star is related to the radius of the star by the formula L =? T4 4? R2 or

This method allows you to find the radius of a star from its temperature and luminosity, since the parameters R, L and T are known.

What is a star?

Star - a luminous gas (plasma) celestial body formed from a gas-dusty environment, in which thermonuclear reactions take place.

The sun is a typical G2 dwarf star with a radius of 696 thousand km.

The largest star belongs to the class of red hypergiants, although difficulties in determining the exact sizes of most stars lead to the fact that it is not possible to say with great certainty which star is the largest in the universe.

Red hypergiants are stars in their very last stages of evolution. When the supply of hydrogen, used as a source of nuclear energy in the central part of the star's core, begins to deplete, a stage of internal changes begins, as a result of which the outer layers of the star expand greatly. The red hypergiant consists of a vast envelope of very rarefied gas that surrounds the star's central core.

Hypergiants - these are stars of enormous size and mass, having a luminosity class of 0 in the Hertzsprung-Russell diagram (the diagram shows the relationship between the absolute stellar magnitude, spectral class, luminosity, and temperature of the star's surface), hypergiant stars are defined as the most powerful, heaviest, brightest and at the same time the rarest and short-lived supergiants.

What is the largest star in the universe?

The equatorial radius of the Sun, 695,500 km, is used as a unit for measuring the radius of stars.

As mentioned above, the exact size order of the largest stars is difficult to determine. many large stars have extended atmospheres and opaque dust envelopes and disks, or even pulsate.

In the very first place in some of the largest stars in the universe is a star
VY Big Dog(lat.VY Canis Majoris, VY CMa). The distance from Earth to the largest star in the universe, VY Canis Major, is approximately 5,000 light years. The radius of the star was determined in 2005 and is in the range of 1800-2100 solar radii. The mass of the largest star is ~ 15-25 solar masses.

The second largest stars in space belongs to a star WOH G64 located in the Large Magellanic Cloud galaxy. The radius is 1738 solar radii.

In third place is a large star VV Cephei A, with a radius of 1600-1900 radii of Sonets.

In fourth place is the star Mu Cephei(? Cep /? Cephei), better known as "Herschel's garnet star" - is a red supergiant located in the constellation Cepheus. The radius of the star is 1650 times the radius of a star called the Sun.

The fifth place is taken by a star KY Swan- a star located in the constellation Cygnus at a distance of about 5153 light years from us. This is one of the largest stars known to science. The radius is 1420 solar radii.

The ratio of the sizes of the planets of the solar system and some well-known stars, including VY Canis Major:

1 mercury

5 Aldebaran

6 Betelgeuse

What is the heaviest (massive) star in the Universe?

On June 21, 2010, astronomers led by Paul Crowter, professor of astrophysics at the University of Sheffield, while studying a huge number of star clusters, discovered a star whose mass is much greater than the mass of the Sun.

Scientists have discovered several stars with surface temperatures in excess of 40,000 degrees. It is more than seven times hotter than the temperature on the Sun and several million times brighter. Some of these stars were born with a mass of more than 150 solar masses.

The heaviest star, named R136a1, is from cluster RMC 136a (better known as R136), a cluster of young, massive and hottest stars located within the Tarantula Nebula in the Large Magellanic Cloud, 165,000 light-years from planet Earth. The R136a1 star is one of the most powerful stars in the universe, with a luminosity of 10 million times that of the Sun. The mass of R136a1 is 265 solar masses and a radius of 67 solar radii.

What is the closest star to the solar system?

The closest star to Earth after the Sun is Proxima Centauri, which is 4.243 ± 0.002 light years from Earth, which is 270,000 times more distance from the Earth to the Sun star. The star Proxima Centauri is a red dwarf orbiting the Alpha Centauri system.

The mass of Proxima Centauri is 0.123 ± 0.006 solar masses, which is 7 times less than the mass of the Sun and 150 times more than the mass of the planet Jupiter. Age 4.85 × 109 years. Temperature 3042 ± 117 K. Radius 0.145 ± 0.011 solar radii, i.e. the actual diameter is 7 times less than the diameter of the Sun's star and only 1.5 times the diameter of the planet Jupiter.

What is the brightest star in the night sky?

Sirius is the brightest star in the sky, from the constellation Canis Major. The star Sirius can be observed from almost any region of the Earth, with the exception of only its northernmost regions. Sirius is one of the stars closest to us and is only 8.6 light years distant from the solar system. The brightness of Sirius is 23 times that of the Sun. Originally Sirius consisted of two most powerful blue stars of spectral class A, now the age of this double star about 230 million years.

The brightest star in the universe is the star Pollux in the constellation Gemini. Although it is very difficult to determine the brightest star. Also in the list of the brightest stars stars compete: Shaula (constellation Scorpio); Gakrux (constellation of the Southern Cross); Castor (in the constellation Gemini). The Pistol Star is one of the brightest stars in our Galaxy. The luminosity of the star Pistol exceeds 1.7 million luminosities of the Sun, i.e. in 20 seconds, the Pistol star emits as much light as the Sun emits in a whole year.

What is the largest star in the universe?