See what is the largest planet. What is a planet

August 25, 2014

Amazing spectacle

Just a year ago, scientists with the help of ALMA telescopes saw a stunning sight - the creation of a huge planet in the Milky Way galaxy, which was given the title of the largest planet in the Galaxy.

Astronomers from Cardiff University, using the powerful ALMA telescope, were lucky enough to observe the process of the birth of the largest star in the Milky Way Galaxy. The mass of the protostellar cloud was formed 500 times larger in diameter than the Sun, and its luminosity became several orders of magnitude higher.

protostellar cloud

Previously, scientists saw the formation of a protostellar cloud of gases and dust ten thousand light-years from Earth. Under the influence of gravity, it was compressed towards its own center. It was the process of creating a new star, which became the largest in our galaxy.

The mass of the "newborn" is greater than the mass of the Sun by more than 500 times, and the luminosity that this large planet has in the Galaxy is several million times higher than the solar one. Scientists were lucky to observe this rare process and see it in great detail with the help of the world's most powerful radio telescopes. Scientists conducting the study note that a huge cloud of gases and cosmic dust was pulled inward under the forces of gravity, and a young star was formed from long, thread-like cosmic substances.

Nicolas Paretto, lead researcher for the study from Cardiff University, described how ALMA telescopes were able to see the entire process of star creation in minute detail, which will now appear in astronomy textbooks for children around the world. Their mission was to follow the birth of a giant star, and they did a great job of it. They observed the largest protostellar cloud in the entire Milky Way galaxy.

Might be a star

Astronomers directed the telescope to this part of the starry sky not at all by chance, since they guessed that it was in this area that the conditions were most favorable for the formation of huge stars. Although no one dreamed of seeing the creation of the largest star in the Galaxy. Scientists assumed that this protostellar cloud could produce a star that would exceed the mass of the Sun only a hundred times. Therefore, the result of their observations shocked and pleasantly surprised them.

The co-author of the study, a colleague of Nicholas Paretto from the University of Manchester, Gary Fuller, said that such giants are a rarity in our galaxy, and it is incredibly problematic to see them at the time of creation. Star formation occurs very quickly, and the planet does not remain young for long. So the scientist considers these studies more than successful.

star formation

Another member of the research team, Ana Duarte-Cabral, a representative of the University of Bordeaux, said that during the formation of a star, matter was pulled toward the center unevenly. When closely examining the protostellar cloud, scientists noticed dense gas-dust filaments that were attracted to the center the fastest.

Astronomers hope to continue studying this exciting process of formation of huge luminaries with the help of the most powerful radio telescopes in the world and hope that they will be lucky to see the birth of more than one stellar giant.

- then you will certainly be very interested.

Today we will find out what is the largest planet in the solar system. But let's start with the basic concepts.

The largest planets in the solar system

In relation to other celestial bodies, it belongs to the category of "minor planets" of the solar system. We are talking about the largest space objects.

Right now you will learn the most interesting facts about the unique features of the planets of the solar system, which you probably have not heard about before.

planet classification

First of all, you should understand what types of planets are divided into. The solar system is divided into two parts by the main asteroid belt:

To the first belong , and ;
The second group includes , and ;
At the very end is the Kuiper belt.

Astronomers have designated the first four celestial bodies as "terrestrial planets".

In addition to their location in outer space, they are similar to each other in the presence of a core, metals and silicon, as well as a mantle and crust. Land in this list is in first place in terms of volume.

Astronomers call the second four planets "Gas giants". They significantly exceed the dimensions of the planets of the terrestrial group. The uniqueness of the largest planets lies in the fact that they are rich in the presence of various gases: hydrogen, methane, ammonia and helium.

Is Pluto a planet or not?

In 2006, scientists decided that Pluto should be classified as dwarf planets, including it in the Kuiper belt. According to astronomers, Pluto does not meet any of the conditions by which it is customary to determine full-fledged planets.

The main argument is that Pluto lacks the mass to clear its orbit of other objects. As a result of these scientific studies in the solar system, instead of the traditional 9 planets, there was one less.

The largest planet in the solar system

The largest planet in the solar system is Jupiter, which belongs to the category of gas giants. According to astronomers, he has repeatedly protected our Earth from meteorites.

Planet Jupiter

Since we found out that Jupiter has the status of "The largest planet", let's look at some interesting facts about him.

Striking dimensions

Jupiter is 1300 times larger than Earth. To make it easier to understand, the following comparison should be made: if the Earth could be reduced to the size of a pea, then Jupiter in relation to it would have the size of a basketball.

Comparative sizes of Jupiter and Earth

Also amazing is the speed of rotation of this giant planet. Jupiter makes 1 revolution around its axis in 10 hours at a speed of 13.07 km/s.

In order for the largest planet to manage to pass once in its orbit, 12 Earth years must pass. However, this is quite a bit, considering that Jupiter is 5 times farther from the Sun than our Earth.

ephemeral surface

Did you know that no one will ever be able to set foot on the surface of Jupiter? And all due to the fact that the atmosphere of the largest planet consists of helium and hydrogen in proportions of 1:9.

In fact, it flows into hydrogen. In simple terms, as such, there is simply no distinction between the atmosphere and the surface of this giant. The boundaries of Jupiter are very blurry and abstract, and are determined only by the difference in pressure.

Clouds and spots

Looking at images of Jupiter, it is easy to notice specific striped patterns on them. In fact, these are clouds: light zones alternate with red-brown belts.

Between them pass strong wind currents, which are called jets. They can move in completely different directions.

The main feature of Jupiter

Another unique feature of Jupiter is the Great Red Spot (GRS). It is the largest atmospheric vortex in the solar system.

Such formations in terms of brightness and persistence have not been found on any other planet. Interestingly, the BKP can move around Jupiter, changing only the longitude. Latitude has remained unchanged for more than 350 years.

In addition, at times the spot either increases or decreases. But in general, the trend is decreasing.

According to the latest data from researchers: The Great Red Spot is a huge anticyclone that makes 1 revolution in 6 days.

The second largest planet in the solar system

The second largest among the planets is Saturn. He is very easy to recognize in photographs due to his remarkable rings.

By the way, all gas giants have exactly such rings, they are just not so noticeable. In their composition, along with heavy elements and cosmic dust, there are ice particles.

Saturn also contains methane, helium, hydrogen and ammonia, and continuous winds rage on the surface.

Ice giants

Following Saturn in descending magnitude are Uranus and Neptune. Scientists classify these planets as ice giants, due to the absence of metallic hydrogen in them, and a huge amount of ice.

The uniqueness of Uranus lies in the tilt of its axis. This planet literally lies on its side, which is why the sun's rays alternately illuminate only its poles.

Strong winds constantly rage on Neptune. You can also find a characteristic formation on it, in many ways similar to the Great Red Spot. Astronomers have named this area the Great Dark Spot (also known as GDS-89).

So, now you know that the largest planet in the solar system is Jupiter. However, Saturn, Uranus and Neptune are also giant planets and have their own unique features.

Speaking frankly, it still has very modest knowledge about what is happening in our solar system, not to mention the universe as a whole.

One thing is for sure: there will be many interesting discoveries in the future.

Seemingly inconspicuous UY Shield

Modern astrophysics in terms of stars seems to be re-experiencing its infancy. Observations of the stars give more questions than answers. Therefore, when asking which star is the largest in the Universe, you need to be immediately ready for answers. Are you asking about the largest star known to science, or about what limits science limits a star to? As is usually the case, in both cases you will not get a definitive answer. The most likely candidate for the largest star quite equally shares the palm with his "neighbors". As for how much it can be less than the real "king of the star" also remains open.

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

The supergiant UY Scutum, with some reservation, can be called the largest star observed today. Why "with reservation" will be said below. UY Scutum is 9500 light-years away and is seen as a dim variable star visible through a small telescope. According to astronomers, its radius exceeds 1700 radii of the Sun, and during the pulsation period this size can increase to as much as 2000.

It turns out that if such a star were placed in the place of the Sun, the current orbits of a terrestrial planet would be in the bowels of a supergiant, and the boundaries of its photosphere would sometimes 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.

To fly around such a star at the speed of light will take as much as 7-8 hours. Recall 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 imagine these scales, given that the ISS flies 20 times faster than a bullet and tens of times faster than passenger airliners.

Mass and Luminosity of 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 that the average density of this supergiant is almost a million times lower than the density of the air surrounding us! For comparison, the density of the Sun is one and a half times 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 a conditional boundary between the earth's atmosphere and space. It turns out that the density of the UY Shield is only a little short of the vacuum of space!

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

Physical parameters of the UY Shield

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

At the moment, the star is approaching the final stages of its evolution. Like all supergiants, she began to actively burn helium and some other heavier elements. According to modern models, in a matter of millions of years UY Scutum 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 shed its shell, most likely leaving behind a neutron star.

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

Giants among the stars

Returning to the reservation mentioned above, we note that the primacy of UY Shield as the largest known star cannot be called unequivocal. The fact is that astronomers still cannot determine the distance to most stars with a sufficient degree of accuracy, and therefore estimate their size. In addition, large stars tend to be very unstable (recall the UY Scutum pulsation). Similarly, they have a rather blurry structure. They may have a fairly extended atmosphere, opaque gas and dust shells, disks, or a large companion star (an example is VV Cephei, see below). It is impossible to say exactly where the boundary of such stars passes. In the end, the well-established concept of the boundary of stars as the radius of their photosphere is already extremely arbitrary.

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 (including 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 hyper). Each of them in a matter of millions, or even 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 in UY Shield, this feature is the previously discussed variability. WOH G64 has a toroidal gas and dust envelope. Extremely interesting is the double eclipsing variable star VV Cephei. It is a close system of two stars, consisting of the red hypergiant VV Cephei A and the blue main sequence star VV Cephei B. The centers of these stars are located from each other in some 17-34 . Considering that the VV radius of Cepheus B can reach 9 AU. (1900 solar radii), the stars are located at "arm's length" from each other. Their tandem is so close that whole pieces of the hypergiant flow with great 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 one talk about the size of a star if its atmosphere flows into another star, or smoothly passes into a gas and dust disk? 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, you can be sure that a neutron star is now pulsating in its place or a black hole is bending space, surrounded by the remnants of a supernova explosion. If such a star is even thousands of light years away from us, one cannot be completely sure that it still exists or has remained the same giant.

Add to this the imperfection of modern methods for determining the distance to 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 to lead the Big Ten. This does not mean at all that its leadership is undeniable and that, for example, NML Cygnus or VY Canis Major cannot be larger than her. Therefore, different sources can answer the question about the largest known star in different ways. This speaks rather not about their incompetence, but about 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 discovered stars, how can we say 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 greater than 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 smaller part of them. The fact that the largest stars can be distinguished by their luminosity will not help in the search for a “stellar leader”. Whatever their brightness is, it will fade when observing distant galaxies. Moreover, as noted earlier, the brightest stars are not the largest (an example is R136).

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

Hypergiants

If the largest star is impossible to find practically, 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. Even here, however, modern science faces a problem. The current theoretical model of the evolution and physics of stars does not explain much of what actually exists and is observed in telescopes. An example of this is the hypergiants.

Astronomers have repeatedly had to raise the bar for the limit of stellar mass. This limit was first introduced in 1924 by the English astrophysicist Arthur Eddington. Having obtained 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 hydrostatic equilibrium. The light pressure of the increasing brightness will literally blow away the outer layers of the star. The limit calculated by Eddington was 65 solar masses. Subsequently, astrophysicists refined his calculations by adding unaccounted components to them and using powerful computers. So the modern theoretical limit for the mass of stars is 150 solar masses. Now 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 the fingers. Such stars are called hypergiants. Note that R136a1 is much smaller than the stars that, it would seem, should be below it in class - for example, the supergiant UY Shield. This is because hypergiants are called 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 bar for the mass of a hypergiant has not been established, but, as a rule, their mass exceeds 100 solar masses. None of the biggest stars of the "Big Ten" falls short of these limits.

Theoretical impasse

Modern science cannot explain the nature of the existence of stars whose mass exceeds 150 solar masses. This raises the question of how a theoretical limit to the size of stars can be determined if the radius of a star, unlike 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, metallicity of stars can lead to radical changes in their structure. Astrophysicists have only to comprehend the surprises that will be presented to them by further observations and theoretical research. 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 farthest corners of our Universe.

It can't be, but it's not. There are planets much larger and more massive. For the entire Universe, our Earth is just a grain of sand lost in it. The solar system is only one of the elements of the galaxy. The Sun is the main component of the Galaxy. Eight planets revolve around the sun. And only the ninth - Pluto - because of it and the mass was removed from the list of rotating planets. Each planet has its own parameters, density, temperature. There are those that consist of gas, there are giant, small, cold, hot, dwarf ones.

So what is the largest planet known at the moment? In the spring of 2006, an event occurred that shook the theory of celestial bodies. In the Lovell Observatory (USA, Arizona) in the constellation Hercules, a huge planet was discovered, exceeding the size of our Earth by twenty times. Of the existing open ones today, this is the largest planet in the Universe. It is hot and similar to the Sun, but it is still a planet. They named it TrES-4. Its dimensions exceed the dimensions of the largest planet in the solar system - Jupiter - by 1.7 times. It is a giant gaseous ball. TrES-4 consists mainly of hydrogen. The largest planet makes revolutions around a star, which is located at a distance of 1400. The temperature regime on its surface is more than 1260 degrees.

There are a sufficient number of giant planets, but so far no larger one than TrES-4b has been discovered. The largest planet is larger than Jupiter by more than 70%. A huge gaseous giant could be called a star, but its rotation around its star GSC02620-00648 definitely classifies it as planetary. Its density ranges from 0.2 g per cubic centimeter, which is comparable only to balsa (cork) wood. Astronomers are at a loss as to how this largest planet with such a low density has the ability to exist. The planet TrES-4 is also called TrES-4b. It owes its discovery to amateur astronomers who discovered TrES-4 thanks to a network of small automated telescopes located in the Canary Islands and in

If you watch this planet from the earth, you can clearly see that it is moving along the disk of its star. An exoplanet orbits a star in just 3.55 days. Planet TrES-4 is heavier and hotter than the Sun.

The discoverers were employees of Lowell, and later astronomers and the Hawaiian Observatory W.M. Keck confirmed this discovery. Scientists at the Lovell Observatory have an assumption that the largest planet TrES-4 is not the only one in this constellation, and that it is quite possible that there may be another planet in the constellation Hercules. Employees Lowell in 1930 discovered the world in the solar system - Pluto. However, in 2006, Pluto, compared to the giant TrES-4, began to be called a dwarf planet.

The science

Of course, the oceans are vast, and the mountains are incredibly high. What's more, the 7 billion people that the Earth is home to is also an incredibly 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 the largest planet in our star system. Ancient astronomers named this planet after Jupiter, the father of the Roman gods. 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 the mass of the Earth, and the diameter is 11 times greater. The mass of this giant is 70 percent of the mass of all the planets in the solar system. Jupiter's volume is large enough to contain 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, most of the rest of the mass is Jupiter. At present, the Sun is made up of 70 percent hydrogen and 28 percent helium, with only 2 percent of its mass remaining.

Over time, the hydrogen in the Sun's core turns into helium. Conditions in the Sun's core, which is 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 includes 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 satellites, millions of solid asteroids and billions of icy comets.

4) Star VY Canis Major

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

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

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

5) Huge deposits of water

Astronomers have discovered the largest and most massive reservoir of water ever found in the universe. The giant cloud, 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 located 12 billion light-years from Earth. This discovery shows that water has dominated the universe for almost its entire 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, weighing hundreds or even thousands of millions of solar masses. Most, if not all, galaxies, including the Milky Way, are believed to contain supermassive black holes at their centers.

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

7) Milky Way

100-120 thousand light years in diameter

The Milky Way is a broken spiral galaxy that contains 200-400 billion stars. There are many planets revolving around each of these stars.

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 conditions for the origin of life like Earth.

8) El Gordo

The largest cluster of galaxies (2 10 15 solar masses)*

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

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

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

9) Our Universe

Size - 156 billion light years

Of course, no one could ever name the exact dimensions of the Universe, but, according to some estimates, its diameter is 1.5 * 10 24 kilometers. In general, it is difficult for us to imagine that there is an end somewhere, because the Universe includes incredibly gigantic objects:

Earth Diameter: 1.27*104km

Sun diameter: 1.39*106 km

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

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

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

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

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

10) Multiverse

One can try to imagine not one, but many Universes that exist at the same time. The Multiverse (or Multiple Universe) is a possible collection of many possible Universes, including our own, which collectively comprise everything that exists or can exist: the integrity of the cosmos, time, material matter and energy, and the physical laws and constants that all this describe.

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