Life on our entire planet depends on the Sun, and sometimes we do not realize that in fact there are many other galaxies in the Universe and within them. And our almighty Sun is just a small star among billions of other luminaries. Our article will tell you the name of the largest star in the world, which can still be covered by the human mind. Perhaps, beyond its borders, in hitherto unexplored worlds, there are even more gigantic stars of immense size ...

Measure stars in suns

Before talking about the name of the largest star, we clarify that the size of stars is usually measured in solar radii, its size is 696,392 kilometers. Many of the stars in our galaxy are larger than the Sun in many ways. Most of them belong to the class of red supergiants - large massive stars with a dense hot core and a sparse shell. Their temperature is noticeably lower than the temperature of blue and - 8000-30,000 K (on the Kelvin scale) and 2000-5000 K, respectively. Red stars are called cold, although in fact their temperature is slightly less than the maximum in the core of our Earth (6000 K).

Most celestial objects do not have constant parameters (including size), but rather are in constant change. Such stars are called variable - their sizes change regularly. This can happen for various reasons. Some variable stars are actually a system of several bodies exchanging masses, others are pulsating due to internal physical processes, shrinking and growing again.

What is the name of the largest star in the universe?

At a distance of 9.5 thousand light years from the Sun, it appeared on star maps at the end of the 17th century, thanks to the Polish astronomer Jan Hevelius. And two hundred years later, German astronomers from the Bonn Observatory added the star UY Shield (U-Ygrek) to the catalog. And already in our time, in 2012, it was found that UY Scuti is the largest of the known stars within the studied Universe.

The radius of the UY Scutum is about 1700 times greater than the radius of the Sun. This red hypergiant is a variable star, which means that its dimensions can reach even larger values. During periods of maximum expansion, the radius of the UY Shield is 1900 solar radii. The volume of this star can be compared with a sphere, the radius of which would be the distance from the center of the solar system to Jupiter.

Giants of Space: what are the names of the largest stars

In the neighboring galaxy, the Large Magellanic Cloud, is the second largest star within the studied space. Its name cannot be called particularly memorable - WOH G64, but you can take note that it is located in the constellation Dorado, a constant visible in the southern hemisphere. In size, it is slightly smaller than UY Scutum - about 1500 solar radii. But it has an interesting shape - the accumulation of a rarefied shell around the nucleus forms a spherical shape, but rather resembles a donut or bagel. Scientifically, this shape is called a torus.

According to another version, what is the name of the largest star after UY Shield, the leader is VY Canis Major. It is believed that its radius is equal to 1420 solar. But the surface of VY Canis Majoris is too rarefied - the Earth's atmosphere exceeds it in density by several thousand times. Due to the difficulty in determining what is the actual surface of the star, and what is already its accompanying shell, scientists still cannot come to a final conclusion regarding the size of VY Canis Major.

The heaviest stars

If we consider not the radius, but the mass of the celestial body, then the largest star is called as a set of letters and numbers in encryption - R136a1. It is also located in the Large Magellanic Cloud, but it belongs to the type of blue stars. Its mass corresponds to 315 solar masses. For comparison, the mass of the UY Shield is only 7-10 solar masses.

Another massive formation is called Eta Carinae, a double giant star in the 19th century, as a result of an outburst around this system, a nebula formed, named Homunculus because of its strange shape. The mass of Eta Carina is 150-250 solar masses.

The biggest stars in the night sky

The giant stars hiding in the depths of space are inaccessible to the eye of a simple layman - most often they can only be seen through a telescope. At night, in the starry sky, the brightest and closest objects to the Earth will seem large to us - be it stars or planets.

What is the name of the largest star in the sky and at the same time the brightest? This is Sirius, which is one of the closest stars to the Earth. In fact, it is not much larger than the Sun in size and mass - only one and a half to two times. But its brightness is really much greater - 22 times greater than that of the Sun.

Another bright and therefore seemingly large object in the night sky is actually not a star, but a planet. We are talking about Venus, the brightness of which in many respects exceeds the rest of the stars. Its brilliance is visible closer to sunrise or some time after sunset.

With the naked eye, a person can see up to 6 thousand stars in the sky, given both hemispheres. If we take into account the most powerful and complex telescopes, then over the years of space exploration, we have found billions of stars in the abyss of space, among which there are those whose dimensions are beyond imagination.

We are surprised when we compare the sizes of our Earth and the Sun, but the Universe hides in itself the largest stars, which are thousands of times larger than ours. Let's do our favorite thing - size comparison. It is customary to take the equatorial solar radius as a unit of measurement.

1. UY Shield

UY Shield is the absolute record holder in terms of size among all the stars known to us at the moment. It is located at a distance of 9500 light years from us. The radius of the largest star is equal to 1708 radii of our Sun, and during active pulsations it reaches 2298 radii. If this monster were located in our system, its photosphere (visible disk) would reach the orbit of Jupiter.

Next to UY Shield, the Sun would not even seem like a dwarf - a speck of dust. This star is very bright, but it will not be possible to see it with the naked eye due to the large thickness of cosmic dust between us and this hypergiant.

2. NML Cygnus

Another red hypergiant, which is located in the constellation Cygnus, received the corresponding name - NML Cygnus. The photo shows the star cluster in which this supermassive star is located. Its radius is equal to 1650 radii of our Sun, and it is 5300 light years away from us.

Compared to UY Shield, NML Cygnus was discovered relatively recently - in 1965. Since then, scientists have even managed to analyze the composition of the star using spectral analysis. As for her size, it's good that she's so far away.

3. RW Cephei

Looking at these giants, it is easy to earn an inferiority complex. Third place in our list of the largest stars went to the red hypergiant RW Cephei, located in the constellation of the same name. This star is 11,500 light years away from us, and despite its size, you are unlikely to be able to see it with the naked eye. But there is a chance to see this monster in the night sky with an amateur telescope.

The RW radius of Cephei is 1636 solar at its peak pulsation. And it rushes towards our Sun at a speed of 56 km / s. It sounds menacing, but by cosmic standards it's like standing still. Scientists predict her future in the form of another black hole.

4. WOH G64

Interesting things happen to them there in space. For example, the fourth largest in the list of the largest stars WOH G64 is located at a distance of 163 thousand light years from us. The word "huge" for such a distance does not mean anything, however, our scientists managed to find out some facts about this luminary that make this star special. According to recent studies, its radius is 1540 solar, but the luminosity is not very high.

With the help of a powerful telescope located in Chile, it turned out that around the star WOH G64 there is a large accumulation of gas and dust, which form a so-called torus around it (call it a donut).

5. Westerland 1-26

Scientists are also not devoid of romantic thinking, and are ready to give eloquent names to their discoveries. So in the Westerland 1 cluster in the constellation Altar there is another red supergiant called Westerland 1-26. It is 11,500 light-years away from our system. The radius of the star is 1530 solar, and its luminosity is 380,000 times stronger than that of the Sun.

The system was discovered in 1961, but the creative fuse of the scientists ended, and they simply began to call the stars in that system by numbers.

One of the popular ways of presenting information today is to compile ratings - finding out the tallest person in the world, the longest river, the oldest tree, etc. There are such ratings in the world of astronomy - the science of the stars.


From school lessons, we know well that our Sun, which gives our planet heat and light, is very small on the scale of the Universe. Stars of this type are called yellow dwarfs, and among the countless millions of luminaries, many much larger and more spectacular astronomical objects can be found.

"Star" life cycle

Before looking for the largest star, let's remember how stars live and what stages they go through in their development cycle.

As you know, stars are formed from giant clouds of interstellar dust and gas, which gradually become denser, increase in mass and, under the influence of their own gravity, are compressed more and more. The temperature inside the cluster gradually increases, while the diameter decreases.

The phase, which indicates that an astronomical object has become a full-fledged star, lasts 7-8 billion years. Depending on the temperature, stars can be blue, yellow, red, etc. in this phase. The color is determined by the mass of the star and the physical and chemical processes taking place in it.


But any luminary eventually begins to cool down and at the same time expand in volume, turning into a "red giant", the diameter of which exceeds the original star by tens or even hundreds of times. At this time, the star can pulsate, either expanding or contracting in diameter.

This period lasts several hundred million years and ends with an explosion, after which the remnants of the star are compressed, forming a dim "white dwarf", neutron star or "black hole".

So, if we are looking for the largest star in the Universe, then it will most likely be a “red giant” - a star in the aging phase.

The biggest star

To date, astronomers know quite a lot of "red giants", which can be called the largest stars in the observable part of the universe. Since this type of star is subject to pulsation, in different years the leaders in magnitude were considered:

- KY Cygnus - the mass exceeds the mass of the Sun by 25 times, and the diameter is 1450 solar;

- VV Cephei - with a diameter of about 1200 solar;

- VY Canis Major - is considered the largest in our Galaxy, its diameter is about 1540 solar diameters;

- VX Sagittarius - the diameter in the maximum phase of the pulsation reaches 1520 solar;

- WOH G64 - a star from the nearest neighboring galaxy to us, the diameter of which reaches, according to various estimates, 1500-1700 solar;


- RW Cephei - with a diameter of 1630 solar diameters;

- NML Cygnus - "red giant", in a circle exceeding 1650 diameters of the Sun;

- Shield UV - today it is considered the largest in the observable part of the Universe, with a diameter of about 1700 diameters of our Sun.

The heaviest star in the universe

Another champion star should be mentioned, which is designated by astronomers as R136a1 and is located in one of the galaxies of the Large Magellanic Cloud. Its diameter is not too impressive yet, but the mass is 256 times the mass of our Sun. This star violates one of the main astrophysical theories, which states that the existence of stars with a mass of more than 150 solar masses is impossible due to the instability of internal processes.

By the way, in accordance with astronomical calculations, R136a1 often lost a fifth of its mass - initially this figure was within 310 solar masses. It is believed that the giant was formed as a result of the merger of several ordinary stars, so it is not stable and can explode at any moment, turning into a supernova.

Even today it exceeds the brightness of the Sun ten million times. If you move R136a1 into our galaxy, it will eclipse the Sun with the same brightness with which the Sun now eclipses the Moon.

The brightest stars in the sky

Of those stars that we can see with the naked eye in the sky, the blue giant Rigel (the constellation of Orion) and the red Deneb (the constellation of Cygnus) have.


The third brightest is the red Betelgeuse, which, together with Rigel, makes up the famous Belt of Orion.

Astronomers never cease to delight us with new discoveries, finding more and more stars in the Universe. Some of them can be seen at night with the naked eye, just by looking at the night sky. In order to see others, the most powerful telescopes are required. What is the largest star in the universe? Where is it located and how is it different from its neighbors? We invite you to familiarize yourself with the rating of the largest stars that have already been discovered by astronomers in the universe.

AH Scorpio

This is a real red giant, which is located in the constellation of Scorpio at a distance of 12 thousand light years relative to our planet. Its radius exceeds the radius of the Sun by 1.5 thousand times.

KY Swan

This star, which is located in the constellation Cygnus, will have to fly from the Earth as much as 5 thousand light years. Comparing the radius of the planet with the Sun, we can say that its radius is equal to 1420 solar radii. But the mass of the planet is not so large - it is only 25 times heavier than our star. It could illuminate much more than the Sun, since the brightness of KY Cygnus exceeds the solar one by many millions of times, so it can quite win in the “Brightest” nomination.

VV Cephei A

This double is located in the constellation of the same name, the distance to which is about 5000 light years. It is recognized as one of the largest in its galaxy, second only to VY Canis Major. Estimating the radius along the equator of this star, we can say that it is equal to 1900 equatorial radii of our star.

VY Big Dog

If we consider the Milky Way, then it was this star that became its champion, with a radius exceeding the size of the Sun by more than 1540 times. According to astronomers, this star is very unstable and there is an assumption that over the next 100,000 years it will certainly explode, resulting in a gamma-ray burst that can destroy all life that is within 1-2 light years. As for the planet Earth, only a huge distance from our planet to VY Canis Major, which is about 4000 light years, can save it. Therefore, earthlings can be calm.

VX Sagittarius

Scientists note the pulsation of this variable star, as studies have proven a periodic change in its temperature and volume. And its pulsation can be compared with the beating of a human heart. The equatorial radius of VX Sagittarius is equal to 1520 solar. The star is located in the constellation of the same name, from which it got its name.

Westerland 1-26

The numerical value of the radius of this giant exceeds the solar one by 1540 times. From Earth to Westerland 1-26 is about 11,500 light years.

WOH G64

The star WOH G64 is called the red star. It can be found by exploring the constellation, which has the name Golden Fish, which is located in a galaxy called the Large Magellanic Cloud. Our solar system is about 163,000 light-years away. Its radius is 1730 times greater than that of the Sun. According to research, the star will cease to exist, becoming a supernova. However, this will happen no earlier than in 10-20 thousand years. Although during this time a lot of things can change.

RW Cephei

This giant star has a red color and is located at a distance of more than 2700 light years from Earth. Its radius along the equator is 1636 times greater than the radius of the Sun.

NML Cygnus

The star acquired its name based on the name of the constellation, where it was discovered by astronomers. Its radius exceeds the solar one by 1650 times. A distance of 5300 light years separates us from NML Cygnus. Exploring the structure of the planet, scientists found sulfur oxide, hydrogen sulfide and other substances in it.

UY Shield

Scientists agreed that UY Shield is the largest in the entire universe. The record holder is located in the constellation with the same name at a distance of approximately 9.5 thousand light years from us. The star is very bright, but this is prevented by a huge amount of dust and gas around the planet.