Stars. The difference between stars by color examples, multi-colored stars Red stars names the world around 3

Experts put forward several theories of their occurrence. The most probable of the bottom says that such blue stars were binary for a very long time, and they had a merger process. When 2 stars unite, a new star appears with much greater brightness, mass, temperature.

Blue stars examples:

• Gamma Sails;
• Rigel;
• Zeta Orion;
• Alpha Giraffe;
• Zeta Korma;
• Tau Big Dog.

White stars - white stars

One scientist discovered a very dim star white color, which was a satellite of Sirius and it was named Sirius B. The surface of this unique star is heated to 25,000 Kelvin, and its radius is small.

White stars examples:

• Altair in the constellation Eagle;
• Vega in the constellation Lyra;
• Castor;
• Sirius.

yellow stars - yellow stars

Such stars have a yellow glow, and their mass is within the mass of the Sun - it is about 0.8-1.4. The surface of such stars is usually heated to a temperature of 4-6 thousand Kelvin. Such a star lives for about 10 billion years.

Yellow stars examples:

• Star HD 82943;
• Toliman;
• Dabih;
• Hara;
• Alhita.

red stars red stars

The first red stars were discovered in 1868. Their temperature is quite low, and the outer layers of red giants are filled with a lot of carbon. Previously, such stars made up two spectral classes - N and R, but now scientists have been able to identify another common class - C.

We never think that maybe there is some other life besides our planet, besides our solar system. Perhaps there is life on some of the planets revolving around a blue or white or red, or maybe a yellow star. Perhaps there is another such planet earth, on which the same people live, but we still do not know anything about it. Our satellites and telescopes have discovered a number of planets on which there may be life, but these planets are tens of thousands and even millions of light years away.

Blue stragglers - blue stars

The stars that are in star clusters spherical type, the temperature of which is higher than the temperature of ordinary stars, and the spectrum is characterized by a significant shift to the blue region than that of cluster stars with a similar luminosity, are called blue stragglers. This feature allows them to stand out relative to other stars in this cluster on the Hertzsprung-Russell diagram. The existence of such stars refutes all theories of stellar evolution, the essence of which is that for stars that arose in the same period of time, it is assumed that they will be located in a well-defined region of the Hertzsprung-Russell diagram. In this case, the only factor that affects the exact location of a star is its initial mass. The frequent occurrence of blue stragglers outside of the above curve may be a confirmation of the existence of such a thing as anomalous stellar evolution.

Experts trying to explain the nature of their occurrence put forward several theories. The most probable of them indicates that these blue stars were binary in the past, after which the process of merging began to occur or is currently taking place. The result of the merger of two stars is the formation new star, which has a much greater mass, brightness, and temperature than stars of the same age.

If the correctness of this theory can somehow be proved, the theory of stellar evolution would be free of problems in the form of blue stragglers. The resulting star would have large quantity hydrogen, which would behave similarly to a young star. There are facts to support this theory. Observations have shown that stray stars are most often found in the central regions of globular clusters. As a result of the prevailing number of stars of unit volume there, close passages or collisions become more likely.

To test this hypothesis, it is necessary to study the pulsation of blue stragglers, since between the asteroseismological properties of merged stars and normally pulsating variables, there may be some differences. It should be noted that it is rather difficult to measure pulsations. This process is also negatively affected by the overcrowding of the starry sky, small fluctuations in the pulsations of blue stragglers, as well as the rarity of their variables.

One example of a merger could be observed in August 2008, when such an incident affected the object V1309, the brightness of which increased several tens of thousands of times after detection, and returned to its original value after several months. As a result of 6-year observations, scientists came to the conclusion that this object is two stars, the period of revolution of which around each other is 1.4 days. These facts led scientists to the idea that in August 2008 the process of merging of these two stars took place.

Blue stragglers are characterized by high torque. For example, the rotation speed of the star, which is located in the middle of the 47 Tucanae cluster, is 75 times the rotation speed of the Sun. According to the hypothesis, their mass is 2-3 times the mass of other stars that are located in the cluster. Also, with the help of research, it was found that if blue stars are close to any other stars, then the latter will have a percentage of oxygen and carbon lower than their neighbors. Presumably, the stars pull these substances from other stars moving in their orbit, as a result of which their brightness and temperature increase. The “robbed” stars reveal places where the process of transformation of the initial carbon into other elements took place.

Blue Star Names - Examples

Rigel, Gamma Sails, Alpha Giraffe, Zeta Orion, Tau Canis Major, Zeta Puppis

White stars - white stars

Friedrich Bessel, who led the Koenigsberg Observatory, made an interesting discovery in 1844. The scientist noticed the slightest deviation of the brightest star in the sky - Sirius, from its trajectory in the sky. The astronomer suggested that Sirius had a satellite, and also calculated the approximate period of rotation of stars around their center of mass, which was about fifty years. Bessel did not find proper support from other scientists, because. no one could detect the satellite, although in terms of its mass it should have been comparable to Sirius.

And only 18 years later, Alvan Graham Clark, who was testing the best telescope of those times, discovered a dim white star near Sirius, which turned out to be his satellite, called Sirius B.

The surface of this white star is heated to 25 thousand Kelvin, and its radius is small. Taking this into account, scientists concluded that the satellite has a high density (at the level of 106 g/cm 3 , while the density of Sirius itself is approximately 0.25 g/cm 3 , and that of the Sun is 1.4 g/cm 3 ). After 55 years (in 1917), another white dwarf was discovered, named after the scientist who discovered it - van Maanen's star, which is located in the constellation Pisces.

Names of white stars - examples

Vega in the constellation Lyra, Altair in the constellation Eagle, (visible in summer and autumn), Sirius, Castor.

yellow stars - yellow stars

Yellow dwarfs are called small main sequence stars, the mass of which is within the mass of the Sun (0.8-1.4). Judging by the name, such stars have a yellow glow, which is released during the thermonuclear process of fusion from helium hydrogen.

The surface of such stars is heated to a temperature of 5-6 thousand Kelvin, and their spectral types are between G0V and G9V. A yellow dwarf lives for about 10 billion years. The combustion of hydrogen in a star causes it to multiply in size and become a red giant. One example of a red giant is Aldebaran. Such stars can form planetary nebulae by shedding their outer layers of gas. In this case, the core is transformed into a white dwarf, which has a high density.

If we take into account the Hertzsprung-Russell diagram, then on it the yellow stars are in the central part of the main sequence. Since the Sun can be called a typical yellow dwarf, its model is quite suitable for considering the general model of yellow dwarfs. But there are other characteristic yellow stars in the sky, whose names are Alkhita, Dabikh, Toliman, Hara, etc. These stars are not very bright. For example, the same Toliman, which, if you do not take into account Proxima Centauri, is closest to the Sun, has a magnitude of 0, but at the same time, its brightness is the highest among all yellow dwarfs. This star is located in the constellation Centaurus, it is also a link in a complex system, which includes 6 stars. The spectral class of Toliman is G. But Dabih, located 350 light years from us, belongs to the spectral class F. But its high brightness is due to the presence of a nearby star belonging to the spectral class - A0.

In addition to Toliman, HD82943 has spectral type G, which is located on the main sequence. This star, due to its chemical composition and temperature similar to the Sun, also has two large planets. However, the shape of the orbits of these planets is far from circular, so their approaches to HD82943 occur relatively often. Currently, astronomers have been able to prove that this star used to have a much larger number of planets, but over time it swallowed them all.

Yellow Star Names - Examples

Toliman, star HD 82943, Hara, Dabih, Alhita

Red stars - red stars

If at least once in your life you have seen red stars in the sky in the lens of your telescope, which burned against a black background, then the memory this moment will help to more clearly present what will be written in this article. If you have never seen such stars, next time be sure to try to find them.

If you undertake to compile a list of the brightest red stars in the sky, which can be easily found even with the help of amateur telescope, then you can find that they are all carbon. The first red stars were discovered in 1868. The temperature of such red giants is low, in addition, their outer layers are filled with huge amount carbon. If earlier similar stars made up two spectral classes - R and N, now scientists have identified them in one general class - C. Each spectral class has subclasses - from 9 to 0. At the same time, class C0 means that the star has a high temperature, but less red than C9 stars. It is also important that all carbon-dominated stars are inherently variable: long-period, semi-regular, or irregular.

In addition, two stars, called red semi-regular variables, were included in such a list, the most famous of which is m Cephei. William Herschel also became interested in her unusual red color, who dubbed her “pomegranate”. Such stars are characterized by an irregular change in luminosity, which can last from a couple of tens to several hundred days. Such variable stars belong to the class M (cold stars, the surface temperature of which is from 2400 to 3800 K).

Given the fact that all the stars in the rating are variables, it is necessary to introduce some clarity in the designations. It is generally accepted that red stars have a name that consists of two constituent parts- letters Latin alphabet and the name of the variable constellation (for example, T Hare). The first variable that was discovered in this constellation is assigned the letter R and so on, up to the letter Z. If there are many such variables, a double combination of Latin letters is provided for them - from RR to ZZ. This method allows you to "name" 334 objects. In addition, stars can also be designated using the letter V in combination with a serial number (V228 Cygnus). The first column of the rating is reserved for the designation of variables.

The next two columns in the table indicate the location of the stars in the period 2000.0. As a result of the increased popularity of Uranometria 2000.0 among astronomy enthusiasts, the last column of the rating displays the number of the search chart for each star that is in the rating. In this case, the first digit is a display of the volume number, and the second - serial number cards.

The rating also displays the maximum and minimum brightness values ​​of stellar magnitudes. It is worth remembering that a greater saturation of red color is observed in stars whose brightness is minimal. For stars whose period of variability is known, it is displayed as a number of days, but objects that do not have the correct period are displayed as Irr.

It doesn't take much skill to find a carbon star, it's enough that your telescope has enough power to see it. Even if its size is small, its pronounced red color should draw your attention. Therefore, do not be upset if you cannot immediately find them. It is enough to use the atlas to find a nearby bright star, and then move from it to the red one.

Different observers see carbon stars differently. To some, they resemble rubies or an ember burning in the distance. Others see crimson or blood red hues in such stars. For starters, there is a list of the six brightest red stars in the ranking, and if you find them, you can enjoy their beauty to the fullest.

Red Star Names - Examples

Differences in stars by color

There is a huge variety of stars with indescribable color shades. As a result, even one constellation has received the name "Jewel Box", which is based on blue and sapphire stars, and in its very center is a brightly shining orange star. If we consider the Sun, then it has a pale yellow color.

A direct factor influencing the difference in color of stars is their surface temperature. It is explained simply. Light by its nature is radiation in the form of waves. Wavelength - this is the distance between its crests, is very small. To imagine it, you need to divide 1 cm into 100 thousand identical parts. A few of these particles will make up the wavelength of light.

Considering that this number turns out to be quite small, each, even the most insignificant, change in it will cause the picture we observe to change. After all, our vision perceives different wavelengths of light waves as different colors. For example, blue has waves whose length is 1.5 times less than that of red.

Also, almost every one of us knows that temperature can have the most direct influence on the color of the bodies For example, you can take any metal object and put it on fire. As it heats up, it will turn red. If the temperature of the fire increased significantly, the color of the object would also change - from red to orange, from orange to yellow, from yellow to white, and finally from white to blue-white.

Since the Sun has a surface temperature in the region of 5.5 thousand 0 C, it is typical example yellow stars. But the hottest blue stars can warm up to 33 thousand degrees.

Color and temperature have been linked by scientists with the help of physical laws. The temperature of a body is directly proportional to its radiation and inversely proportional to the wavelength. Waves of blue color have shorter wavelengths than red. Hot gases emit photons whose energy is directly proportional to the temperature and inversely proportional to the wavelength. That is why the blue-blue range of radiation is characteristic of the hottest stars.

Since the nuclear fuel on the stars is not unlimited, it tends to be consumed, which leads to the cooling of the stars. Therefore, middle-aged stars are yellow, and we see old stars as red.

As a result of the fact that the Sun is very close to our planet, its color can be accurately described. But for stars that are a million light-years away, the task becomes more complicated. It is for this purpose that a device called a spectrograph is used. Through it, scientists pass the light emitted by the stars, as a result of which it is possible to analyze almost any star spectrally.

In addition, using the color of a star, you can determine its age, because. mathematical formulas make it possible to use spectral analysis to determine the temperature of a star, from which it is easy to calculate its age.

Video secrets of the stars watch online

With a telescope, you can observe 2 billion stars up to 21 magnitudes. There is a Harvard spectral classification stars. In it, the spectral types are arranged in order of decreasing stellar temperature. Classes are designated by letters of the Latin alphabet. There are seven of them: O - B - A - P - O - K - M.

A good indicator of the temperature of a star's outer layers is its color. Hot stars of spectral types O and B are blue; stars similar to our Sun (whose spectral type is 02) appear yellow, while stars of spectral classes K and M are red.

Brightness and color of stars

All stars have a color. There are blue, white, yellow, yellowish, orange and red stars. For example, Betelgeuse is a red star, Castor is white, Capella is yellow. By brightness, they are divided into stars 1st, 2nd, ... nth star values ​​(n max = 25). The term "magnitude" has nothing to do with true dimensions. The magnitude characterizes the light flux coming to Earth from a star. Stellar magnitudes can be both fractional and negative. The magnitude scale is based on the perception of light by the eye. The division of stars into stellar magnitudes according to apparent brightness was carried out by the ancient Greek astronomer Hipparchus (180 - 110 BC). Most bright stars Hipparchus attributed the first magnitude; he considered the next in brightness gradation (i.e., about 2.5 times weaker) to be stars of the second magnitude; stars weaker than stars of the second magnitude by 2.5 times were called stars of the third magnitude, etc.; stars at the limit of visibility to the naked eye were assigned a sixth magnitude.

With such a gradation of the brightness of the stars, it turned out that the stars of the sixth magnitude are weaker than the stars of the first magnitude by 2.55 times. Therefore, in 1856, the English astronomer N. K. Pogsoy (1829-1891) proposed to consider as stars of the sixth magnitude those that are exactly 100 times fainter than the stars of the first magnitude. All stars are located at different distances from the Earth. It would be easier to compare magnitudes if the distances were equal.

The magnitude that a star would have at a distance of 10 parsecs is called absolute magnitude. The absolute stellar magnitude is indicated - M, and the apparent stellar magnitude - m.

The chemical composition of the outer layers of stars, from which their radiation comes, is characterized by the complete predominance of hydrogen. In second place is helium, and the content of other elements is quite small.

Temperature and mass of stars

Knowing the spectral type or color of a star immediately gives the temperature of its surface. Since stars radiate approximately like absolutely black bodies of the corresponding temperature, the power radiated by a unit of their surface per unit time is determined from the Stefan-Boltzmann law.

The division of stars based on a comparison of the luminosity of stars with their temperature and color and absolute magnitude (Hertzsprung-Russell diagram):

1. the main sequence (in the center of it is the Sun - a yellow dwarf)
2. supergiants (large in size and high luminosity: Antares, Betelgeuse)
3. red giant sequence
4. dwarfs (white - Sirius)
5. subdwarfs
6. white-blue sequence

This division is also based on the age of the star.

The following stars are distinguished:

1. ordinary (Sun);
2. double (Mizar, Albkor) are divided into:

• a) visual double, if their duality is noticed when observing through a telescope;
• b) multiples - this is a system of stars with a number greater than 2, but less than 10;
• c) optical-double - these are stars that their proximity is the result of a random projection onto the sky, and in space they are far away;
• d) physical binaries are stars that form single system and circulate under the action of forces of mutual attraction around a common center of mass;
• e) spectroscopic binaries are stars that, when mutually revolving, come close to each other and their duality can be determined from the spectrum;
• e) eclipsing binary - these are stars "which, when mutually revolving, block each other;

variables (b Cephei). Cepheids are variables in the brightness of a star. The amplitude of the change in brightness is no more than 1.5 magnitudes. These are pulsating stars, that is, they periodically expand and contract. The compression of the outer layers causes them to heat up;

non-stationary.

new stars- these are stars that existed for a long time, but suddenly flared up. Their brightness increased a short time 10,000 times (amplitude of brightness change from 7 to 14 magnitudes).

supernovae- these are stars that were invisible in the sky, but suddenly flashed and increased in brightness 1000 times relative to ordinary new stars.

Pulsar - neutron star generated during a supernova explosion.

Data about total number pulsars and their lifetimes indicate that, on average, 2-3 pulsars are born per century, which approximately coincides with the frequency of supernova explosions in the Galaxy.

Star evolution

Like all bodies in nature, stars do not remain unchanged, they are born, evolve, and finally die. Astronomers used to think that it took millions of years for a star to form from interstellar gas and dust. But in last years photographs were taken of a region of the sky that is part of the Great Nebula of Orion, where a small cluster of stars appeared over the course of several years. In the photographs of 1947, a group of three star-like objects was recorded in this place. By 1954 some of them had become oblong, and by 1959 these oblong formations had disintegrated into individual stars. For the first time in the history of mankind, people observed the birth of stars literally before our eyes.

In many parts of the sky, there are conditions necessary for the appearance of stars. When studying photographs of foggy areas Milky Way managed to detect small black spots of irregular shape, or globules, which are massive accumulations of dust and gas. These gas and dust clouds contain dust particles that very strongly absorb the light coming from the stars behind them. The size of the globules is huge - up to several light years in diameter. Despite the fact that the matter in these clusters is very rarefied, their total volume is so large that it is quite enough to form small clusters of stars close in mass to the Sun.

In a black globule, under the influence of radiation pressure emitted by surrounding stars, the matter is compressed and compacted. Such compression proceeds for some time, depending on the sources of radiation surrounding the globule and the intensity of the latter. The gravitational forces arising from the concentration of mass in the center of the globule also tend to compress the globule, causing matter to fall towards its center. Falling, the particles of matter acquire kinetic energy and the gasopes heat up the left cloud.

The fall of matter can last hundreds of years. At first, it occurs slowly, unhurriedly, since the gravitational forces that attract particles to the center are still very weak. After some time, when the globule becomes smaller and the gravitational field increases, the fall begins to occur faster. But the globule is huge, no less than a light year in diameter. This means that the distance from its outer border to the center can exceed 10 trillion kilometers. If a particle from the edge of the globule starts to fall towards the center at a speed slightly less than 2 km/s, then it will reach the center only after 200,000 years.

The lifespan of a star depends on its mass. Stars With a mass less than that of the Sun use their nuclear fuel very sparingly and can shine for tens of billions of years. The outer layers of stars like our Sun, with masses no greater than 1.2 solar masses, gradually expand and, in the end, completely leave the core of the star. In place of the giant remains a small and hot white dwarf.

World of celestial bodies

People have long treated the sun with love and special respect. After all, already in antiquity, they realized that without the sun, neither a person, nor an animal, nor a plant can live.
The sun is the closest star to the earth. Like other stars, this is a huge hot celestial body that constantly radiates light and heat. The sun is a source of light and heat for all life on Earth.

Using the information, write the numbers into the text.
The diameter of the Sun is 109 times the diameter of the Earth. The mass of the Sun is 330,000 times the mass of our planet. The distance from the Earth to the Sun is 150 million kilometers. The temperature on the surface of the Sun reaches 6 thousand degrees, and in the center of the Sun - 15 - 20 million degrees.

With the naked eye, a person can see about 6,000 stars in the night sky. Scientists know many billions of stars.
Stars vary in size, color, brightness.
By color, white, blue, yellow and red stars are distinguished.

The sun belongs to the yellow stars.

Blue stars are the hottest, followed by white, then yellow, and the coldest are red stars.
The brightest stars emit 100,000 times more light than the Sun. But there are also those that shine a million times weaker than the Sun.

The difference between stars by color

The sun and those moving around it celestial bodies make up the solar system. Build a model of the solar system. To do this, mold planet models from plasticine and arrange them in the correct sequence on a sheet of cardboard. Sign the names of the planets on the plates and stick them on your model.

Solve the crossword.

open blank crossword>>

1. The largest planet in the solar system. Answer: Jupiter
2. A planet with rings that are clearly visible in a telescope. Answer: Saturn
3. The closest planet to the Sun. Answer: Mercury
4. The planet farthest from the Sun. Answer: Neptune
5. The planet we live on. Answer: Earth
6. Planet - a neighbor of the Earth, located closer to the Sun than the Earth. Answer: Venus
7. Planet - a neighbor of the Earth, located farther from the Sun than the Earth.
Answer: Mars
8. Planet located between Saturn and Neptune. Answer: Uranus

Using various sources of information, prepare a report about a star, constellation, or planet that you would like to learn more about. Write down the basic information for your message.

Mars one of the five planets in the solar system that can be seen from Earth naked eye. From Earth, it looks like a small red dot, which is why Mars is sometimes referred to as the Red Planet. The planet bears the name of the ancient Roman god of war, it has two satellites Phobos and Deimos. These are the names of the two sons of the god of war, they are translated as "Fear" and "Horror". Mars is the fourth planet from the Sun. In many ways, it is very similar to Earth. It has an atmosphere, on Mars there is a change of seasons. At both poles of the planet, as on Earth, there are ice caps. Mars is almost half the size of our planet.

Values. By general agreement, these scales are chosen so that a white star, like Sirius, has the same magnitude on both scales. The difference between the photographic and photovisual quantities is called the color index of a given star. For such blue stars as Rigel, this number will be negative, since such stars on an ordinary plate give a greater blackening than on a yellow-sensitive one.

For red stars like Betelgeuse, the color index reaches + 2-3 magnitudes. This measurement of color is also a measurement of the surface temperature of the star, with blue stars being much hotter than red ones.

Since color indices can be obtained quite easily even for very faint stars, they have great importance when studying the distribution of stars in space.

Instruments are among the most important tools for studying stars. Even the most superficial look at the spectra of stars reveals that they are not all the same. The Balmer lines of hydrogen are strong in some spectra, weak in some, and absent altogether in some.

It soon became clear that the spectra of stars can be divided into a small number of classes, gradually passing into each other. The current spectral classification was developed at the Harvard Observatory under the direction of E. Pickering.

At first, the spectral classes were denoted by Latin letters in alphabetical order, but in the process of refining the classification, the following designations for successive classes were established: O, B, A, F, G, K, M. In addition, a few unusual stars are combined into classes R, N and S , and individual individuals who do not fit into this classification at all are designated by the symbol PEC (peculiar - special).

It is interesting to note that the arrangement of stars by class is also an arrangement by color.

• Class B stars, to which Rigel and many other stars in Orion belong, are blue;
• classes O and A - white (Sirius, Deneb);
• classes F and G - yellow (Procyon, Capella);
• classes K and M - orange and red (Arcturus, Aldebaran, Antares, Betelgeuse).

Arranging the spectra in the same order, we see how the maximum of the emission intensity shifts from the violet to the red end of the spectrum. This indicates a decrease in temperature as one moves from class O to class M. A star's place in the sequence is determined more by its surface temperature than by its chemical composition. It is generally accepted that chemical composition the same for the vast majority of stars, but different surface temperatures and pressures cause large differences in stellar spectra.

Blue class O stars are the hottest. Their surface temperature reaches 100,000°C. Their spectra are easily recognizable by the presence of some characteristic bright lines or by the propagation of the background far into the ultraviolet region.

They are directly followed class B blue stars, are also very hot (surface temperature 25,000°C). Their spectra contain lines of helium and hydrogen. The former weaken, while the latter strengthen in the transition to class A.

V classes F and G(a typical G-class star is our Sun) the lines of calcium and other metals, such as iron and magnesium, gradually increase.

V class K calcium lines are very strong, and molecular bands also appear.

Class M includes red stars with surface temperature, less than 3000°C; bands of titanium oxide are visible in their spectra.

Classes R, N and S belong to the parallel branch of cool stars whose spectra contain other molecular components.

To the connoisseur, however, there is a very big difference between "cold" and "hot" class B stars. In a precise classification system, each class is subdivided into several more subclasses. The hottest class B stars are subclass VO, stars with an average temperature for this class - k subclass B5, the coldest stars - to subclass B9. The stars are directly behind them. subclass AO.

The study of the spectra of stars turns out to be very useful, since it makes it possible to roughly classify stars according to their absolute magnitudes. For example, the VZ star is a giant with an absolute magnitude of approximately -2.5. It is possible, however, that the star will be ten times brighter (absolute value - 5.0) or ten times fainter (absolute value 0.0), since it is impossible to give a more accurate estimate from the spectral type alone.

When establishing a classification of stellar spectra, it is very important to try to separate giants from dwarfs within each spectral class, or, where this division does not exist, to single out from the normal sequence of giants stars that have too high or too low luminosity.