Mass of supergiants. Giant and dwarf stars. Heavy and light

Living our lives on the satellite of a small star on the outskirts of the Universe, we cannot even imagine its true scope. The dimensions of the Sun seem incredible to us, and even the star is larger, it simply does not fit into our imagination. What can we say about monster stars - super and hyper giants next to which our Sun is no more than a speck of dust.

The star is located in the Constellation of the Altar, being the largest space object in it. It was discovered by an astronomer from Sweden, Västerlund, whose name it was named in 1961.

The mass of Westerland 1-26 exceeds the Sun by 35 times. Brightness of 400,000. Still see a star naked eye impossible due to its huge distance from our planet, which is 13,500,000 light years. If you place Westerland in our solar system, its outer shell will engulf the orbit of Jupiter.

Giant from the Large Magellanic Cloud. The size of the star is almost 3 billion kilometers (1540 - 2000 solar radii), the distance to WOH G64 is 163 thousand light years. years.

The star has long been considered the largest, but recent studies have shown that its radius has significantly decreased, and according to some estimates for 2009, it amounted to 1540 sizes of our star. Scientists suspect that strong stellar wind is to blame

UY Shield

in the constellation Milky Way, and in the entire universe known to mankind, it is the brightest, and one of the largest stars. The removal of this red supergiant from Earth is 9,600 light years. The diameter changes quite actively (at least according to observations from the Earth), so we can talk about an average of 1708 solar diameters.

The star belongs to the category of red supergiants, its luminosity exceeds the solar one by 120,000 times. Accumulated around, for billions of years of existence of the star, cosmic dust and gas, significantly reduce the luminosity of the star, so it is impossible to determine it more accurately.

Jupiter would be completely engulfed along with its orbit if the Sun had the dimensions of UY Scutum. Oddly enough, for all its greatness, the star is only 10 times more massive than our star.

The star belongs to the class of binary, 5000 light-years away from the Earth. About 1700 times larger than our Sun in linear dimensions. VV Cephei A is considered one of the largest studied stars in our Galaxy.

The history of its observations dates back to 1937. It was studied mainly by Russian astronomers. The conducted studies have revealed the periodicity of the dimming of the star once every 20 Earth years. It is considered one of the brightest stars in our galaxy. The mass of VV Cepheus A exceeds the solar mass by about 80-100 times.

Radius space object 1535 times greater than the sun, about 50 times the mass. The brightness index RW of Cepheus is 650,000 times higher than that of the Sun. The surface temperature of a celestial object ranges from 3500 to 4200 K, depending on the intensity of thermonuclear reactions in the bowels of the star.

Super bright variable hypergiant from the constellation Sagittarius. VX Sagittarius pulsates in long irregular periods. This is the most studied supergiant star, its radius is 850 - 1940 solar and tends to decrease.

The distance from Earth to this yellow supergiant is 12,000 light years. The mass is equal to 39 solar (despite the fact that the mass of the star itself is 45 times greater than the mass of the Sun). The size of V766 Centauri is amazing, it is 1490 times larger than our Sun in diameter.

The yellow giant is located in a system of two stars, representing their part. The location of the second star of this system is such that it touches V766 Centauri with its outer shell. The described object has a luminosity exceeding the solar one by 1,000,000 times.

According to some reports, the largest star in the known universe, its radius, according to some calculations, can reach 2850 solar. But more often it is accepted as 1420.

Mass VY Big Dog exceeds the mass of the Sun by 17 times. The star was discovered at the beginning of the century before last. Later studies added information about all its main characteristics. The size of the star is so large that it takes eight light years to fly around its equator.

The red giant is located in the constellation Canis Major. According to the latest scientific data, within the next 100 years, a star will explode, and it will turn into a supernova. The distance from our planet is approximately 4500 light years, which in itself eliminates any danger from the explosion to mankind.

The diameter of this star, which belongs to the category of red supergiants, is approximately 1411 solar diameters. Removal of AH Scorpio from our planet is 8900 light years.

The star is surrounded by a dense shell of dust, a fact confirmed by numerous photographs taken through telescopic observation. The processes occurring in the bowels of the luminary cause the changeability of the brightness of the star.

The mass of AH Scorpio is equal to 16 solar masses, the diameter exceeds the solar one by 1200 times. The maximum surface temperature is assumed to be 10,000 K, but this value is not fixed and can change both in one direction and in the other.

This star is also known as Herschel's Garnet Star after the astronomer who discovered it. It is located in the constellation of the same name Cepheus, it is triple, it is separated from the Earth at a distance of 5600 light years.

The main star of the system, MU Cepheus A, is a red supergiant whose radius, according to various estimates, exceeds the solar one by 1300-1650 times. The mass is 30 times greater than the Sun, the temperature at the surface is from 2000 to 2500 K. The luminosity of MU Cepheus exceeds the Sun by more than 360,000 times.

This red supergiant belongs to the category of variable objects, located in the constellation Cygnus. The approximate distance from the Sun is 5500 light years.

The radius of BI Cygnus is approximately from 916-1240 solar radii. The mass exceeds our star by 20 times, the luminosity is 25,000 times. The temperature of the upper layer of this space object is from 3500 to 3800 K. According to recent studies, the temperature on the surface of the star varies greatly due to intense thermonuclear reactions of the interior. During the period of the greatest bursts of thermonuclear activity, the surface temperature can reach 5500 K.

A supergiant discovered in 1872, which becomes a hypergiant during the maximum pulsation. The distance to S Perseus is 2420 parsecs, the pulsation radius is from 780 to 1230 r.s.

This red supergiant belongs to the category of irregular, variable objects with unpredictable pulsation. It is located in the constellation Cepheus, 10,500 light years away. It is 45 times more massive than the Sun, the radius is 1500 times greater than the solar one, which in digital terms is approximately 1,100,000,000 kilometers.

If we conditionally place V354 Cepheus in the center solar system, Saturn would be inside its surface.

This red giant is also a variable star. A semi-correct, fairly bright object is located at a distance of about 9600 light years from our planet.

The radius of the star is within 1190-1940 solar radii. The mass is 30 times more. The surface temperature of the object is 3700 K, the luminosity index of the star exceeds that of the Sun by 250,000 - 280,000 times.

largest famous star. At a temperature of 2300 K, its radius increases to 2775 solar, which is almost a third larger than any star known to us.

In the normal state, this indicator is 1183.

The space object is located in the constellation Cygnus, refers to red variable supergiants. The average distance from our planet, according to the calculations of astronomers, is from 4600 to 5800 light years. The estimate of the radius of a celestial object is from 856 to 1553 solar radii. Such a run-up of indicators is due to the different level of pulsation of the star in different periods time.

The mass of BC Cygnus is from 18 to 22 solar mass units. The surface temperature is from 2900 to 3700 K, the luminosity value is about 150,000 times higher than the sun.

This well-studied variable star supergiant is located in the Carina Nebula. The approximate distance of a space object from the Sun is 8500 light years.

Estimates of the radius of the red giant vary significantly, ranging from 1090 to the radius of our star. The mass is 16 times greater than the mass of the Sun, the value of the surface temperature is 3700-3900 K. The average luminosity of a star is from 130,000 to 190,000 solar.

This red giant is located in the constellation Centaurus, the distance from our planet, according to various estimates, is from 8,500 to 10,000 light years. To date, the object has been studied relatively little, there is little information about it. It is only known that the radius of V396 Centauri exceeds the similar parameter of the Sun by about 1070 times. Presumably, the temperature on the surface of the star is also estimated. According to rough estimates, it is in the range of 3800 - 45,000 K.

CK Carina refers to the so-called "variable" stellar objects, located in the constellation Carina, at a distance of approximately 7500 light-years from our planet. Its radius exceeds the Sun by 1060 times. Astronomers have calculated that if this object were located in the center of the solar system, the planet Mars would be on its surface.

The star has a mass exceeding the mass of the Sun by about 25 times. Luminosity - 170,000 Suns, surface temperature at the level of 3550 K.

The star is a red supergiant with a mass of 10 to 20 solar masses. Located in the constellation Sagittarius, distance celestial body from our planet is 20,000 light years. The radius, according to the maximum estimates, is approximately 1460 solar.

The luminosity exceeds the solar one by 250,000 times. The temperature on the surface is from 3500 to 4000 K.

With high luminosity [up to 10 5 -10 6 solar luminosities (Lʘ)] and low effective temperature (3000-5000 K).

According to the Yerkes spectral classification, they belong respectively to spectral classes K and M and luminosity classes III and I (or 0 in the case of the most massive red supergiants - the so-called hypergiants). The radii of red giants reach hundreds of solar radii (Rʘ), and red supergiants reach thousands of Rʘ. Red giants and supergiants emit predominantly in the red and IR regions of the spectrum. Feature spectra of red giants and supergiants - the presence of emission lines of metals, H and K lines Ca II, Ca I, molecular absorption bands. Typical red giants include Aldebaran (luminosity ≈ 160Lʘ, radius ≈ 25Rʘ), red supergiants - Betelgeuse (≈ 7 10 4 Lʘ, ≈ 700Rʘ).

Stars fall into the region of the Hertzsprung-Russell diagram, occupied by red giants and supergiants, as a result of the expansion of their shells after hydrogen burns out in the cores of stars (see Evolution of stars). Stars with masses from ≈ 1 solar mass (Mʘ) to ≈ (8-10)Mʘ become red giants. Stars with masses from ≈ (8-10) Mʘ to ≈ 40 Mʘ turn into red supergiants. Initially, red giants and supergiants have helium cores surrounded by a layer in which hydrogen thermonuclear combustion occurs. When the temperature in the center of the star T c reaches ≈ 2·10 8 K, helium combustion begins. Helium burnout leads to the formation of carbon-oxygen nuclei (Fig.), Surrounded by two unstable combustion layers - helium and hydrogen (the so-called giants of the asymptotic branch). The matter in the cores of red giants is degenerate.

Red giants and supergiants are characterized by an intense outflow of matter (stellar wind), the flow of which can reach 10 -5 -10 -4 Mʘ per year. The stellar wind arises under the influence of radiation pressure, pulsation instability, shock waves in the crowns of stars. The loss of matter and its cooling can lead to the formation of huge gas-dust circumstellar shells that completely absorb the visible radiation of stars.

Such objects radiate in the IR range of the spectrum (the so-called OH / IR stars).

The combustion of hydrogen and helium in layered sources leads to an increase in the masses of the stellar cores; the nuclei shrink and T c increases. However, in red giants with initial masses ≤(8-10)Mʘ, the loss of matter leads to the fact that the masses of their degenerate carbon-oxygen cores do not reach a value at which carbon ignition is possible, and they turn into white dwarfs with masses ≤Mʘ, having passed stage of a planetary nebula. In the cores of more massive stars, carbon, oxygen, neon, magnesium, silicon are sequentially burnt out, and the process of nucleosynthesis ends with the formation of iron (56 Fe) nuclei with a mass of ≈ (1.5-2)Mʘ, which collapse with the formation of neutron stars or black holes. Collapsing red supergiants appear as type II supernovae. The time that stars spend in the red giant or red supergiant stage is about 10% of their total lifetime.

Variable stars of various types are observed among red giants and supergiants: Mirids, semi-regular variables, etc., with pulsation periods from tens of days to several years and brightness variations of up to several magnitudes. Pulsations can be either radial or non-radial. Shock waves propagating in the shells of stars can be superimposed on pulsations.

Stars with chemical composition, close to the solar one, with initial masses ≥40Mʘ, do not reach the red supergiant stage during evolution, since already at the stage of hydrogen combustion in the core they lose most of the hydrogen shell and move to the region of the Hertzsprung-Russell diagram occupied by hot stars (with an effective temperature of up to 10 5 K). A star can also leave the region of red giants or supergiants and move to the region of hotter stars if it is part of a close binary system and loses its envelope as a result of the filling of the Roche lobe.

Lit .: Zeldovich Ya. B., Blinnikov S. P., Shakura N. I. Physical foundations structure and evolution of stars. M., 1981; Zasov A. V., Postnov K. A. General astrophysics. Fryazino, 2006.

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10th place - AH Scorpio

The tenth line of the largest stars in our Universe is occupied by a red supergiant, located in the constellation Scorpio. The equatorial radius of this star is 1287 - 1535 radius of our sun. It is located approximately 12,000 light years from Earth.

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9th place - KY Lebedya

The ninth place is occupied by a star located in the constellation Cygnus at a distance of about 5 thousand light years from Earth. The equatorial radius of this star is 1420 solar radii. However, its mass exceeds the mass of the Sun by only 25 times. Shines KY Cygnus about a million times brighter than the Sun.

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8th place - VV Cepheus A

VV Cephei is an eclipsing Algol-type binary star in the constellation Cepheus, about 5,000 light-years from Earth. It is the second largest star in the Milky Way Galaxy (after VY Canis Major). The equatorial radius of this star is 1050 - 1900 solar radii.

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7th place - VY Big Dog

The largest star in our galaxy. The radius of the star lies in the range 1300 - 1540 radii of the sun. It would take light 8 hours to go around a star in a circle. Studies have shown that the star is unstable. Astronomers predict that VY Canis Major will explode as a hypernova in the next 100,000 years. Theoretically, a hypernova explosion will cause gamma-ray bursts that could damage the contents of the local part of the universe, destroying any cellular life within a radius of several light years, however, the hypergiant is not located close enough to Earth to pose a threat (approximately 4 thousand light years).

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6th place - VX Sagittarius

Giant pulsating variable star. Its volume, as well as the temperature, change periodically. According to astronomers, the equatorial radius of this star is 1520 radii of the sun. The star got its name from the name of the constellation in which it is located. The manifestations of a star due to its pulsation resemble the biorhythms of the human heart.

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5th place - Westerland 1-26

The fifth line is occupied by a red supergiant, the radius of this star lies in the range 1520 - 1540 solar radii. It is located 11,500 light years from Earth. If Westerland 1-26 were at the center of the solar system, its photosphere would encompass the orbit of Jupiter. For example, the typical length of the photosphere in depth for the Sun is 300 km.

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4th place - WOH G64

WOH G64 is a red supergiant located in the constellation Dorado. Located in the neighboring galaxy Large Magellanic Cloud. The distance to the solar system is approximately 163,000 light years. The radius of the star lies in the range 1540 - 1730 solar radii. The star will end its existence and become a supernova in a few thousand or tens of thousands of years.

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3rd place - RW Cepheus

Bronze goes to RW Cephei. The red supergiant is located at a distance of 2739 light years from us. The equatorial radius of this star is 1636 solar radii.

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2nd place - NML Lebedya

The second line of the largest stars in the Universe is occupied by a red hypergiant in the constellation Cygnus. The radius of the star is about 1650 solar radii. The distance to it is estimated at about 5300 light years. As part of the star, astronomers discovered substances such as water, carbon monoxide, hydrogen sulfide, sulfur oxide.

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1st place - UY Shield

The largest star in our universe this moment is a hypergiant in the constellation Scutum. It is located at a distance of 9500 light years from the Sun. The equatorial radius of the star is 1708 radius of our sun. The luminosity of the star is approximately 120,000 times greater than the luminosity of the Sun in the visible part of the spectrum, the brightness would be much higher if there were not a large accumulation of gas and dust around the star.

Supergiant stars - the cosmic fate of these colossal luminaries destined them to burst into a supernova at a certain time.

All stars are born in the same way. A giant cloud of molecular hydrogen begins to shrink into a ball under the influence of gravity until the internal temperature triggers nuclear fusion. Throughout their existence, the luminaries are in a state of struggle with themselves, the outer layer is crushed by the force of gravity, and the core is pressed by the force of the heated substance, which tends to expand. In the process of existence, hydrogen and helium gradually burn out in the center and ordinary luminaries with a significant mass become supergiants. There are such objects in young formations, such as irregular galaxies or open clusters.

Properties and Options

Mass plays a decisive role in the formation of stars - in a large core is synthesized more quantity energy that raises the temperature of the luminary and its activity. Approaching the final segment of existence, objects with a weight exceeding the sun by 10-70 times, pass into the category of supergiants. In the Hertzsprung-Russell diagram, which characterizes the relationship of magnitude, luminosity, temperature and spectral type, such luminaries are located on top, indicating a high (from +5 to +12) apparent magnitude of objects. They are shorter than those of other stars, because they reach their state at the end of the evolutionary process, when the reserves of nuclear fuel are running out. In hot objects, helium and hydrogen run out, and combustion continues due to oxygen and carbon and further up to iron.

Classification of supergiant stars

According to the Yerkes classification, which reflects the subordination of the luminosity spectrum, supergiants belong to class I. They were divided into two groups:

• Ia- bright supergiants or hypergiants;
• Ib are less luminous supergiants.

According to their spectral type in the Harvard classification, these stars occupy the interval from O to M. Blue supergiants are represented by classes O, B, A, red - K, M, intermediate and poorly studied yellow - F, G.

Red supergiants

Large stars leave the main sequence when carbon and oxygen start burning in their core - they become red supergiants. Their gas envelope grows to enormous sizes, spreading over millions of kilometers. Chemical processes that take place with the penetration of convection from the shell into the core lead to the synthesis of heavy elements of the iron peak, which, after the explosion, scatter in space. It is the red supergiants that usually end up life path luminaries and explode in a supernova. The gas envelope of the star gives rise to a new nebula, and the degenerate core turns into a white dwarf. and - the largest objects among the dying red luminaries.

Blue supergiants

Unlike red, long-living giants, these are young and hot stars, exceeding the mass of the sun by 10-50 times, and by a radius of 20-25 times. Their temperature is impressive - it is 20-50 thousand degrees. The surface of blue supergiants is rapidly decreasing due to compression, while the radiation of internal energy is constantly growing and increasing the temperature of the star. The result of this process is the transformation of red supergiants into blue ones. Astronomers have noticed that stars go through various stages in their development, at intermediate stages they turn yellow or white. brightest star Oriona is a great example of a blue supergiant. Its impressive mass is 20 times greater than the Sun, its luminosity is 130 thousand times higher.

Stars are very different: small and large, bright and not very bright, old and young, hot and cold, white, blue, yellow, red, etc.

The Hertzsprung-Russell diagram allows you to understand the classification of stars.

It shows the relationship between absolute magnitude, luminosity, spectral type, and surface temperature of a star. The stars in this diagram are not arranged randomly, but form well-defined areas.

Most of the stars are located on the so-called main sequence. The existence of the main sequence is due to the fact that the hydrogen burning stage is ~90% of the time of evolution of most stars: the burning of hydrogen in the central regions of the star leads to the formation of an isothermal helium core, the transition to the red giant stage, and the departure of the star from the main sequence. The relatively brief evolution of red giants leads, depending on their mass, to the formation of white dwarfs, neutron stars, or black holes.

Being at different stages of their evolutionary development, stars are divided into normal stars, dwarf stars, giant stars.

Normal stars are the main sequence stars. Our sun is one of them. Sometimes such normal stars as the Sun are called yellow dwarfs.

yellow dwarf

A yellow dwarf is a type of small main sequence star with a mass between 0.8 and 1.2 solar masses and a surface temperature of 5000–6000 K.

The lifetime of a yellow dwarf is on average 10 billion years.

After the entire supply of hydrogen burns out, the star increases many times in size and turns into a red giant. An example of this type of star is Aldebaran.

The red giant ejects its outer layers of gas, forming planetary nebulae, and the core collapses into a small, dense white dwarf.

A red giant is a large reddish or orange color. The formation of such stars is possible both at the stage of star formation and at the later stages of their existence.

At an early stage, the star radiates due to the gravitational energy released during compression, until the compression is stopped by the onset of a thermonuclear reaction.

At the later stages of the evolution of stars, after the hydrogen burns out in their interiors, the stars descend from the main sequence and move to the region of red giants and supergiants of the Hertzsprung-Russell diagram: this stage lasts about 10% of the time of the “active” life of stars, that is, the stages of their evolution , during which nucleosynthesis reactions take place in the stellar interior.

The giant star has a relatively low surface temperature, about 5000 degrees. A huge radius, reaching 800 solar and due to such large sizes, a huge luminosity. The maximum radiation falls on the red and infrared regions of the spectrum, which is why they are called red giants.

The largest of the giants turn into red supergiants. A star called Betelgeuse in the constellation Orion is the most striking example of a red supergiant.

Dwarf stars are the opposite of giants and can be as follows.

A white dwarf is what remains of an ordinary star with a mass not exceeding 1.4 solar masses after it passes through the red giant stage.

Due to the absence of hydrogen, a thermonuclear reaction does not occur in the core of such stars.

White dwarfs are very dense. They are not sized more earth, but their mass can be compared with the mass of the Sun.

These are incredibly hot stars, reaching temperatures of 100,000 degrees or more. They shine on their remaining energy, but over time, it runs out, and the core cools down, turning into a black dwarf.

Red dwarfs are the most common stellar-type objects in the universe. Estimates of their abundance range from 70 to 90% of the number of all stars in the galaxy. They are quite different from other stars.

The mass of red dwarfs does not exceed a third of the solar mass (the lower mass limit is 0.08 solar, followed by brown dwarfs), the surface temperature reaches 3500 K. Red dwarfs have a spectral type M or late K. Stars of this type emit very little light, sometimes in 10,000 times smaller than the Sun.

Given their low radiation, none of the red dwarfs are visible from Earth to the naked eye. Even the closest red dwarf to the Sun, Proxima Centauri (the closest star in the triple system to the Sun) and the closest single red dwarf, Barnard's Star, have an apparent magnitude of 11.09 and 9.53, respectively. At the same time, a star with a magnitude of up to 7.72 can be observed with the naked eye.

Due to the low rate of hydrogen combustion, red dwarfs have a very long lifespan - from tens of billions to tens of trillions of years (a red dwarf with a mass of 0.1 solar masses will burn for 10 trillion years).

In red dwarfs, thermonuclear reactions involving helium are impossible, so they cannot turn into red giants. Over time, they gradually shrink and heat up more and more until they use up the entire supply of hydrogen fuel.

Gradually, according to theoretical concepts, they turn into blue dwarfs - a hypothetical class of stars, while none of the red dwarfs has yet managed to turn into a blue dwarf, and then into white dwarfs with a helium core.

Brown dwarf - substellar objects (with masses in the range of approximately 0.01 to 0.08 solar masses, or, respectively, from 12.57 to 80.35 Jupiter masses and a diameter approximately equal to that of Jupiter), in the depths of which, in contrast from main sequence stars, there is no thermonuclear fusion reaction with the conversion of hydrogen into helium.

The minimum temperature of main sequence stars is about 4000 K, the temperature of brown dwarfs lies in the range from 300 to 3000 K. Brown dwarfs constantly cool down throughout their lives, while the larger the dwarf, the slower it cools.

subbrown dwarfs

Subbrown dwarfs or brown subdwarfs are cold formations that lie below the brown dwarf limit in mass. Their mass is less than about one hundredth of the mass of the Sun or, respectively, 12.57 masses of Jupiter, the lower limit is not defined. They are more commonly considered planets, although the scientific community has not yet come to a final conclusion about what is considered a planet and what is a subbrown dwarf.

black dwarf

Black dwarfs are white dwarfs that have cooled down and therefore do not radiate in the visible range. Represents the final stage in the evolution of white dwarfs. The masses of black dwarfs, like the masses of white dwarfs, are limited from above by 1.4 solar masses.

A binary star is two gravitationally bound stars revolving around a common center of mass.

Sometimes there are systems of three or more stars, in such a general case the system is called a multiple star.

In cases where such a star system is not too far removed from the Earth, individual stars can be distinguished through a telescope. If the distance is significant, then to understand that before astronomers a double star is possible only by indirect signs - brightness fluctuations caused by periodic eclipses of one star by another and some others.

New star

Stars that suddenly increase in luminosity by a factor of 10,000. A nova is a binary system consisting of a white dwarf and a main sequence companion star. In such systems, gas from the star gradually flows into the white dwarf and periodically explodes there, causing a burst of luminosity.

Supernova

A supernova is a star that ends its evolution in a catastrophic explosive process. The flare in this case can be several orders of magnitude larger than in the case new star. Such a powerful explosion is a consequence of the processes taking place in the star at the last stage of evolution.

neutron star

Neutron stars (NS) are stellar formations with masses of the order of 1.5 solar masses and sizes noticeably smaller than white dwarfs, the typical radius of a neutron star is, presumably, of the order of 10-20 kilometers.

They consist mainly of neutral subatomic particles - neutrons, tightly compressed by gravitational forces. The density of such stars is extremely high, it is commensurate, and according to some estimates, it can be several times higher than the average density atomic nucleus. One cubic centimeter of NZ matter would weigh hundreds of millions of tons. The force of gravity on the surface of a neutron star is about 100 billion times greater than on Earth.

In our Galaxy, according to scientists, there can be from 100 million to 1 billion neutron stars, that is, somewhere around one in a thousand ordinary stars.

Pulsars

Pulsars are cosmic sources electromagnetic radiation coming to Earth in the form of periodic bursts (pulses).

According to the dominant astrophysical model, pulsars are spinning neutron stars with magnetic field, which is tilted to the axis of rotation. When the Earth falls into the cone formed by this radiation, it is possible to record a radiation pulse that repeats at intervals equal to the period of revolution of the star. Some neutron stars make up to 600 revolutions per second.

cepheid

Cepheids are a class of pulsating variable stars with a fairly accurate period-luminosity relationship, named after the star Delta Cephei. One of the most famous Cepheids is the North Star.

The above list of the main types (types) of stars with their brief description, of course, does not exhaust the entire possible variety of stars in the Universe.