Star

  • What does star mean?
  • The star is a plasma cure, mainly composed of hydrogen and helium, which appears to be a spot in the sky that shines in a dense and dark space. The galaxies formed by the gathered stars are the dominant observable universe. There are about 6,000 stars visible from the Earth with the naked eye, and the closest star to Earth is the Sun, which is also the source of life on earth.

 

  • The main source of energy over the Earth, including daylight, is the Sun. Other stars, when viewed from the earth, appear in the sky when they are not under the sun’s light. The nuclear energy that is emitted in the nucleus reactions (fusion reactions) that sprout in the nuclei of the star’s brilliance is propagated by the outer far-field radiation (radiation) after passing through the star.

 

  • Astronomers can determine the star’s mass, age, chemical composition, and many other properties by observing the spectrum, brightness, and movement of a star. The total mass of a star is the main determinant of the development of the star and the end. The diameter, rotation, motion and temperature of a star are determined according to the stage in which the star is developing. The Hertzsprung-Russell diagram (H-R diagram), which is marked according to temperature and brightness, is used to determine the current age and development of the stars, their stage in the process.

 

  • The first ring of star development is a cloud of matter, consisting of hydrogen, some helium, and heavier amounts of heavier items that begin to collapse inward. After concentrating as much as the nucleus of the star, some of the hydrogen contained therein is continuously helium converted into nucleus fusion reaction. The remainder of the star moves away from the nucleus by virtue of the emptiness, radiation, and convection. These processes prevent the star from collapsing into itself, and the energy is spread outwardly by radiation, creating a star wind on the surface of the star.

 

  • After the hydrogen fuel in the core is exhausted, the star, which at least has a mass of two masses of the mass of the Sun, expands, and the heavier items come in red giant by fusing around the nucleus or the nucleus. Then a part of the material is released into the interstellar atmosphere, transforming into a shape that will create a new star progeny in which heavy items will be more intense.

 

  • In systems of two or more stars, gravity is connected to each other by a force, and usually there are stars rotating in regular orbits around each other. There is a significant effect on the evolutionary development of the interaction of gravitational forces with stars that follow a very close orbit.

 

  • Historical Observation of Stars
  • Stars have an important place in every culture. Stars were used in religious ceremonies and directions. The Gregorian calendar, which is used almost everywhere in the world, is a solar calendar based on the angle of the axis of rotation relative to the closest star, the Sun.
  • The first astronomers, like Tycho Brahe, described the new stars in the night sky and suggested that the sky was unchangeable. In 1584, Giordano Bruno suggested that other stars were actually other suns, that there might be other planets spinning in their orbit, and that some of them might look like Earth. This thought was previously spoken by ancient Greek thinkers Democritus and Epicurus.

 

  • The view that stars are distant suns in the next century is a common thought among astronomers. In order to explain why these stars did not have a gravitational effect on the solar system, Isaac Newton and theologian Richard Bentley suggested that the stars were evenly distributed all over the place.

 

  • The Italian astronomer Geminiano Montanari recorded the changes in the brightness of the Umaci star in 1667. Edmond Halley published the first measurements of a pair of “standing” stars on our behalf, proving that these stars have changed their position since the time of ancient Greek astronomers Ptolemy and Iparhos. The direct measurement of the distance to a star was first performed by Friedrich Bessel in 1838 using the ray-of-sight method for the 61 Cygni star. The Iraqi angle measurements show the vast distances of the stars in the sky to each other.

 

  • The first astronomer William Herschel was the one who decided to explore the distribution of the stars in the sky. In the 1780s he used a series of measuring instruments to count the stars he had observed along the direction of view at 600. With this work, the number of stars has reached the center of the Milky Way in the sky as the result of the increase. His son John Herschel, who repeats the same work in the southern hemisphere, also found the same increase. Beyond other achievements, William Herschel is also known for his finding that some stars are not only in the same aspect of the view, but also physical partners forming the bi-star system.

 

  • Naming stars
  • It is known that the constellation concept existed during the Babylonian period. Old sky observers have imagined that the distinctive arrangements of the stars have created a picture and have identified it with what they see in their myths and in nature. Twelve constellations on the ecliptic circle formed the basis of astrology. Many stars, which are evident, are usually given Arabic or Latin names.

 

  • Some of the constellations and the Sun have their own myths. These were thought to be the souls or gods of the dead. For example, the Umaci star was believed to represent Gorgon Medusa’s vision.

 

  • In ancient Greek religion, some “stars“, later defined as planets, represented important gods. The names of the planets come from these gods: Mercury, Venus, Mars, Jupiter, and Saturn. (Uranus and Neptune are Greek and Roman gods, but both were not known because of their low brightness in ancient times.) The names of these planets were given by later astronomers.

 

  • In the 1600s the names of the constellations were used to name the stars in that part of the sky. The German astronomer Johann Bayer created a set of star maps, describing each constellation with the Greek letters Bayer said. The system, which consists of the numbers used by the British astronomer John Flamsteed, is also called Flamsteed. Many additional annotation systems have been prepared since the star catalogs were released.

 

  • The International Astronomical Union (IAU) is the sole authority in the scientific community to name stars and other celestial bodies, and some private companies claim to sell names to stars, but neither are known or used by the scientific community. Those interested in astronomy see this type of behavior as a type of fraud that targets people who do not know the star’s nomenclature.

 

  • Measurement units
  • Most of the star variables are specified by the MKS measurement system, but sometimes the CGS measurement system is also used (eg brightness is expressed in erg / second). Mass, luminosity, and radius are generally expressed in terms of units based on the Sun’s properties:

 

  • Solar mass calculate:
  • Solar mass calculate

    Solar mass calculate

    kg

 

  • Solar lighting power calculate:
  • Solar lighting power calculate

    Solar lighting power calculate

    watt

 

 

  • Sun radius calculate:
  • Sun radius calculate

    Sun radius calculate

    m

 

  • Large lengths, such as the radius of a gigantic star or the main axis of a dual system, are often specified by astronomical units (AU). An AU is approximately equal to the average distance between Earth and Sun.

 

  • Star formation and development
  • The stars are formed within molecular clouds that are composed of large regions in the high density of space (still less dense than a vacuum chamber on Earth). These clouds are mostly hydrogen and heavier than 23-28% helium. An example of this kind of nebula in stars is the Orion Nebula. As large stars form these clouds, they strongly illuminate and ionize the clouds they are in and create a H II region.
  • Preliminary formation
  • The formation of a star begins with a gravitational instability which is generated within a particle of self-oscillation and is often triggered by shock waves generated by the collision of a supernova (large starbursts) or two stars. Jeans The area that reaches a density of matter enough to satisfy the criteria of indecision begins to collapse under its own gravitational force.
  • When the cloud collapses, discrete clusters are formed, called Bart droplets, composed of intense dust and gas. They can contain up to 50 solar masses. As the bulb collapses and the density increases, the gravitational energy becomes heat and the temperature increases. When the precursor cloud approaches a balanced state in the case of hydrostatic equilibrium, a precursor occurs in the center of the cloud. These pre-sequence stars are usually encircled by a forefoot disc. The gravitational contraction period lasts 10-15 million years.

 

  • Young stars with less mass than two solar masses are called T Tauri star, and stars with higher mass are called Herbig Ae / Be stars. These newborn stars gush through the axis of rotation and form small clouds called the Herbig-Haro object.

 

  • Main Sequence
  • In the 90% of the stars’ lifetimes, hydrogen is converted into helium by high temperature and high pressure nuclear fusion reactions near the nucleus. Such stars are said to be in the mainland and are called dwarf stars. From the beginning of the mother stratum, the helium rate in the star nucleus increases regularly, and so the nucleus fusion of the core slowly increases the temperature and brightness of the star in order to keep the reaction at the desired speed. For example, the sun entering the mainland about 4.6 billion years ago has been estimated to have increased its brightness by 40% since then.

 

  • Each star constantly produces a star wind that causes the gas to flow outward. For most stars, the amount of mass lost is not significant. The sun loses a mass of about 10 to 14 solar masses per year, or about 0.01% of its mass for the entire lifetime. However, very large stars lose material between 10-7 and 10-5 solar masses, which will significantly affect their evolution. Stars starting with a mass larger than 50 solar masses may lose half of their total mass as long as they remain in the mainland.

 

  • The length of time a star will be found in the mainland determines the amount of fuel to be burned and the rate of burning, in other words, the initial mass and brightness. It is estimated that the sun is about 1010 years. Big stars burn their fuels very quickly and their lives are short. Little stars called red dwarves burn their fuels very slowly and maintain their lives between ten and one hundred billion years. Towards the end of their lives they lose their brightness and return to the dark dwarf. The existence of black dwarfs is not yet anticipated since the life span of such stars is greater than the present age of the universe (13.7 billion years).

 

  • Besides mass, the amount of heavier items than helium also plays an important role in the development of stars. In astronomy all heavily helium items are considered “metal” and their chemical concentration is called metallics. The star’s metallicity affects the time it takes to burn the fuel and controls the formation of magnetic fields. And the star changes the wind’s power. The older cluster II stars have a lesser metal than the younger cluster I stars due to the composition of the natural cloud they formed. These clouds have enriched with heavy metals from some of their gas chambers as time passed and old stars were killed.

 

  • Beyond the main sequence
  • At least when the stars with two solar masses consume hydrogen in their nuclei, their outer layers expand and form a red giant by cooling. About 5 billion years later, when the Sun is a giant red, it will be so big that Mercury and possibly Venus will disappear. According to the established models, it is estimated that the Sun will expand to 99% of the Earth’s current orbit (1 astronomical unit or AU). But until then, due to the decrease in the mass of the Sun, the Earth’s orbit will go up to 1.7 AU, and it will be saved from the sun. However, as the brightness of the Sun reaches several thousand times, neither the ocean nor the air-ball (atmosphere) will remain on Earth.

 

  • Big stars
  • Stars with more mass than the nine solar masses become red super giant by expanding helium burns in stages. Once this fuel in the core is exhausted, heavier items than helium continue to fuse into the core. Temperatures and pressures are reduced by as much as the core to carbon core fusion. This process continues with the burning of oxygen, neon, silicon and sulfur. At the end of the star’s life, nucleus fusion may occur in the shells, such as the layers of onion in the star. A different element in each shell suffers from core fusion. Outside is hydrogen, inward helium, and then heavy items.

 

  • The last step is reached when the star starts to produce iron. Since the iron nuclei (atoms) are more tightly bound than the grain nuclei of other heavy elements, they do not remove the energy after the nucleus fusion, so this process consumes energy. Equally lighter items are more tightly bonded than the grain cores, so that the energy does not come to light with the division (fission). In the center of the elderly and very large stars, a large and inert iron core is gathered. Heavier items rise to the surface of the star and become objects called the Wolf-Rayet star. These stars have a dense star wind that escapes the outer gas ball.

 

  • The collapse of stars
  • At the end of its development, a star of average magnitude loses its outer layers and becomes a planetary nebula. If the mass left after the outer gas is poured is less than 1.4 solar masses, a relatively small object (about the Earth) will still shrink as much as the mass. These stars, which are not big enough to create more cognates, are called white dwarfs. Although the stars are defined as plasma corpus, the electron depleted substance in the white cell is no longer plasma. The white dwarf will turn into a black dwarf after a long time.

 

  • In larger stars, the core of the iron continues to fuse until it can no longer support its mass, that is, it grows larger than 1.4 solar masses. The nucleus suddenly collapses when the electrons in the core are directed to proton and erupted with reverse beta resolution or electron capture to form neutrons and neutrinos. The shock waves created by this settler burst into the supernova of the rest of the star. The supernovas are so brilliant that they are brighter than all of them in the short time. They have been observed as “new stars” in places in the Milky Way that have appeared in places that have not seen stars before.

 

  • Most of the material of the star flew away with the explosion of the supernova and formed nebulae like the Crab Nebula. The rest of the neutron star is still there (sometimes showing itself as a Pulse or X-ray burst) or a star large enough to leave a residue equivalent to four solar masses Happens. In a first star, matter is found in the so-called neutron degenerate, and in the nucleus there is a more exotic degenerate substance called QCD. The essence in the darkness is not yet understood.

 

  • The escaping outer layers of the dead stars include heavy items that can be used in the formation of new stars. These heavy items allow the formation of rocky planets. The flow from supernovae and star winds plays an important role in shaping the interstellar medium.

 

  • Popularity of Stars
  • It is a long accepted assumption that the majority of stars constitute pairs in multi-star systems connected by gravity. This is particularly true for O and B class stars, which are particularly large, and 80% are multiple systems. In smaller stars, however, the proportion of single star systems increases; It is known that only 25% of the red dwarves are a wife. Since 85% of all stars are red dwarfs, most stars in the Milky Way are recalled from birth.

 

  • Larger clusters are called star clusters. They are ordered from a few star-star communities to huge global clusters of hundreds of thousands of stars.

 

  • The stars are not regularly dispersed in the atmosphere and normally gathered in the clouds along with the stars and gas. There are hundreds of billion stars in a common galaxy, and there are more than 100 billion (1011) more galaxies in the observable world. In general, although the stars are believed to be only in their galaxies, there are also interstellar stars.
  • Astronomers estimate at least 70 sekstillion (7 × 1022) stars in the observable phase. This is 230 billion times more than the 300 billion stars in our Milky Way.

 

  • The closest star to Earth after the sun is Proxima Centauri, which is 39.9 trillion (1012) kilometers or 4.2 light years away. It takes 4.2 years for this star’s light to reach the world. If we travel at orbit speed (8 kilometers in the morning – 30,000 kilometers per hour) of Space Helicopter, 150,000 years will be required to reach Proxima Centauri. Similar distances are typical of galaxy wheels, including the Sun’s circumference. The stars may be much closer to each other in the center of the galaxies and in the globular clusters, or even farther apart in the galaxy.

 

  • It is considered very rare that stars collide with each other in the clouds due to their low density. However, these conflicts are more frequent in more dense areas such as the center of the galaxy and the core of the globular cloak. As a result of such collisions, there are occurrences known as blue drifts. These are abnormal stars with a higher surface temperature than the stars with the same brightness on the main line.

 

  • Stars Properties
  • Almost all the properties of stars determine the initial mass. Among these features are brightness, size, development of the star, life span and inevitable end.
  • Age of Stars
  • Most stars have ages between 1 billion and 10 billion years. Some stars are close to the age of the observed universe, 13.7 billion years old. (Big Bang) The bigger the star, the shorter the life is, because the larger pressure in the nuclei of big stars causes the hydrogen to burn faster. The greatest stars live on average one million years, while the red dwarf with minimum mass lives between ten and one hundred billion years since they burn their fuels very slowly.
  • Chemical composition of stars
  • In the case of stars, about 70% of their mass is hydrogen, 28% is helium, and the rest are heavy items. In general, the proportion of heavy items is determined by the content of iron in the star gaze because the iron is a frequent element and the absorption lines are measured relatively easily. Because the stars are formed by self-sustaining clouds, they are used to determine the age of chemical composition of a star, as the superannouncements are consistently enriched by heavy elements. The proportion of heavy items may also be indicative of the possibility that the star is a planetary system.
  • The star with the lowest iron content measured to date is HEU327-2326. It only has 200,000 of the sun’s iron content.

 

  • Diameters of stars
  • Because of their great distances to the Earth, all stars outside the Sun appear to the human eye as bright spots that blink in the night sky under the influence of the Earth’s airborne. Because the star wheels are so small in angular dimensions that they can not be seen by optical telescopes on the earth, telescopes with interferometers are needed to take pictures of these objects. The sun is also a star, but it will appear as a wheel and close to the Earth to provide daylight. The star in the largest visible dimension after the sun is the R Doradus star, which is only 0.057 SOA angular diameter.
  • The stars are arranged in ascending stars such as Betelgeuse, which is about 1.6 billion kilometers in diameter, 1,000 times bigger than the Sun, in the constellation of Orion, not bigger than a city. However, the intensity of Betelgeuse is much less than that of the Sun.

 

  • Star Moving
  • The movement of a star relative to the Sun can provide important information about the structure of the star as well as the structure of the star and the development of the galaxy.
  • It is the tangential velocity of a star’s self. To determine this, very sensitive skies are made annually using the master (mill SOA) unit. By determining the angle of a star, it can be converted to a star’s velocity units of velocity. Stars with high autocorrelation are stars that are closer to the Sun and are good candidates for the measurement of the angle of the sun.
  • Vertical speed is the speed of the star to the sun or away from the sun. This speed is determined by the doppler shift in the spectral line and is in kilometers per second.
  • Once both velocities are determined, the velocity of a star relative to the Sun or the sky can be determined. Among nearby stars, group I stars are found to have lower speeds than older group II stars. Phrase II stars have elliptical orbits that are inclined to the galactic plane. As a result of comparing the movements of nearby stars, star communities were also identified. They most likely shared the same gigantic natural clouds at the origin of their formations.

 

  • Mass of Stars
  • One of the largest known stars is the star of Eta Carinae, which is 100 to 150 times larger than the mass of the Sun and has a very short life span of several million years. A recent study in the Arches cluster suggests that 150 solar masses are the upper limit during the period in which the universe is located. Although the exact cause of this limitation is unclear, Eddington is thought to be responsible for lighting power, which determines the highest amount of lighting power that can be passed, in part, from a star’s gas without having to miss gas.
  • The stars formed immediately after the Big Bang may be 300 solar masses or larger due to the absence of heavier elements than lithium in their composition. These extreme large Height III stars have been extinct for too long and are only found theoretically.
  • AB Doradus C star, the wife of AB Doradus the star with a mass of 93 times the mass of the planet Jupiter, is the smallest star known to have nucleus fusion in its nucleus. The minimum mass in the solar-like metal, which theoretically still can nucleate in the nucleus, is estimated to be approximately 75 times Jupiter. But when the metallicity is low, a study of faint stars shows that the minimum star dimension is 8.3% of the sun, about 87 times the mass of Jupiter. Stars smaller in size are called brown dwarfs, and are located in a region that is not well defined between stars and gas giants.
  • The radius of the star and mass specify the gravitational surface. Giant stars have a lower surface gravity than the stars in the main sequence, while degenerate stars like the white dwarf have greater surface gravity. Surface gravity affects the spectrum of starburst; Broadens the higher gravitational absorption lines.

 

  • Rotation of Stars
  • The rotation speed of the stars can be estimated approximately by rainfall or can be determined more precisely by monitoring the rotation speed of star stains. Young stars have great rotational speeds of over 100 km / h in their equator. For example, class B star Achernar has a swivel speed of about 225 km / h or greater, which leads to a double diameter of 50% greater than the distance between the poles. When this speed is reached, it is a speed that is slightly less than 300 km / h, which is the critical speed at which the star will collide. When compared, the Sun only revolves every 25 to 35 days and the equatorial rotation speed is 1,994 km / s. As the star continues to develop on the main series, the magnetic field and star wind reduce the speed of rotation significantly.
  • Degenerated stars have a high rotational speed because they are compacted in a dense mass. However, angular momentum conservation (increasing the rotation speed in spite of a reduction in the size of a rotating element) has considerably lower rotational speeds than expected. An important part of the angular motion of the star is scattered by the mass loss that occurs at the end of the star wind. Besides, the speed of rotation of a Pulsar is quite high. For example, in the center of the Crab Nebula, the roundabout turns 30 times. The rotation speed of the arc will gradually decrease due to radiation.

 

  • Temperature
  • The surface temperature of a star in the main sequence is determined by the energy production rate of the core and the radius of the star. Large stars can have surface temperatures of up to 50,000 K. Smaller stars such as the sun have a surface temperature of several thousand degrees. Although the red giants have a relatively low surface temperature of 3,600 K, they have high gloss due to their very large surface area.
  • The stellar temperature defines the characteristic absorption lines on the spectrum as different elements can determine the energy gain or ionization rate. The surface temperature of a star is used to classify stars with apparent absolute magnitude (absolute magnitude) and absorption properties.

 

  • Star Ray
  • The energy produced by the stars as a product of the nucleus fusion spreads both as electromagnetism radiation (electromagnetic radiation) and as particle radiation. Spreading particle radiation on the star side manifests itself as a regular neutrinos flow out of the star nucleus (star-like flow of electrically charged particles such as free protons, alpha particles, and beta particles that radiate from the outer layers of the star).

 

  • The energy production in the core is the reason why the stars are so bright. Whenever an item merges two or more atomic (atomic) nuclei to form a atomic nucleus of a heavier element, the gamma ray emits the photon through the nucleus fusion reaction that occurs when it fuses. When this energy reaches the outer layers of the star, it turns into other electromagnetic energy, including visible light.

 

  • The color (frequency) determined by the number of peak vibrations of a visible light of a star is tied to the outer layers of the star, including the light bulb (photoreceptor). In addition to visible light, stars also emit types of electromagnetism that the human eye can not see. Actually, the electromagnetism radiation of stars is radio waves with the longest wavelength of the electromagnetical spectrum (electromagnetic spectrum), and the ultraviolet, which is the shortest wavelength from the infrared, covers the entire range up to the X-ray and gamma ray. All the visible or invisible components of the electromagnetism radiation of the stars are important to distinguish their properties.

 

  • Astronomers who use star spectra can determine the surface temperature, surface gravity, metallicity, and rotation speed of the star. If the distance to the star is also known by its divergent angle measurement, its brightness can also be determined. Then mass, radius, surface gravity and rotation frequency (frequency) can be estimated by looking at star models. The mass of the stars in the binary star system can be measured directly. The gravitational micrometering method also determines the mass of a star.) Astronomers using these variables can also predict the age of the star.

 

  • Brightness of Stars
  • Brightness in astronomy is the amount of light or other radiation energy that a star is emitting at one time. The brightness of a star is determined by its radius and surface temperature.
  • The regions seen on the surface and having a low average temperature and brightness are called star streaks. Small, dwarf stars like the sun generally have wheels with little stars in very small quantities. Larger gigantic stars have bigger and obvious stars, and strong star edges show. This is the decrease in brightness towards the edges of the star wheel. As with the UV Ceti, red dwarf stars can show quite pronounced star formation.
  • Brightness class
  • The brightness of a star is measured by the apparent brightness. This concept determines the brightness of the star according to the distance that it is from the Earth and the change it is going through when passing through the atmosphere.
  • Absolute glare If the distance between the star and Earth is 10 parsecs (32.6 light years), what is the brightness class and depends directly on the brightness of the star.
  • Both visible and absolute brightness class scale logarithm numbers. A number variation in the brightness class is equivalent to an increase of about 2.5 times the brightness (the fifth root of 100 is about 2,512). That is, a star in the first brightness class (+1.00) is 2.5 times brighter than a star in the second brightness class (+ 2.00), and 100 times brighter than a star in the sixth brightness class (+6.00). The obscured stars visible in appropriate viewing conditions are in the +6 luminosity class.
  • The stars become brighter as the number of classes of brightness decreases both in visible and absolute brightness class sizes. On both scales, the brightest stars are in the minus brightness class. To calculate the brightness difference between two stars, the luminosity class of the bright star (mb) is subtracted from the brightness class (mf) of the dimmer star, and the difference is taken as the number of the number 2,512
  • The absolute brightness class (M) and the apparent brightness class (m) of a star do not exactly match each other, depending on both brightness and distance from the Earth; For example, Sirius, a bright star, has an apparent brightness class of -1.44, but the absolute brightness class is only + 1.41.
  • The sun‘s visible brightness class is -26.7 but the absolute brightness class is only +4.83. The brightest star in the sky at night is Sirius, about 23 times brighter than the Sun, the second brightest star in the night sky, 14,000 times brighter than the Sun, with its absolute magnitude of -5.53. Although Canopus is brighter than Sirius, Sirius appears brighter. The reason is that Sirius is only 8.6 light-years away from Earth, but Canopus is 310 light-years away.
  • It is the star with the highest absolute brightness class known as 2006 -14,2 and the LBV 1806-20 star. This star is 38 million times brighter than the Sun. Stars with the least known brightness are found in NGC 6397. The darkest red dwarf in this cluster has a luminosity class of 26, but a white dwarf with 28 luminosity classes was also found. These stars have such a faint light that their moonlight on the moon is as long as the Earth’s appearance.

 

  • Classification of Stars
  • From class O stars, which are very hot compared to their spectra, there are different star classifications up to the class M stars, which are so cold that the matter (molecule) can form in their gas pockets. Classes in the main star classification by decreasing surface temperatures are: O, B, A, F, G, K, and M. There are also special classifications for stars with rare spectral characteristics. The most common of these types are the L-class for the coldest low-mass stars and the T-class for the brown dwarf.
  • There are 10 subclasses of each alphabet, ranging from 0 to 9 (the warmest to the coldest). If this system is quite compatible with the temperatures, the system will be degraded if it goes to the hotest point; O0 and O1 class stars may not exist.
  • In addition, it can be classified according to the “spatial effects” of stars corresponding to the spatial dimension and surface gravity. The stars in this measure are ordered from class 0 (overseers) to class III (giants), class V (main series dwarf) to class VII (white dwarf). Most of the stars are found in the main line of ordinary hydrogen-burning stars. They are placed on a narrow band when they are classified by absolute power classes and spectrum types. The sun is a G2V-type yellow cucumber located on the main line with medium temperature and ordinary size.
  • A lowercase letter is used to indicate the specific characteristics of the spectrum with an additional name. For example, the letter “e” indicates the presence of emission lines (emission lines), while the letter “m” indicates the ultra-high metal level. “Var” indicates changes in spectral type.
  • The white dwarfs have their own classifications starting with the letter D. Depending on the type of lines that are obvious to the band, they are divided into subdivisions DB, DC, DO, DZ, and DQ. This is done by inserting numbers specifying the temperature sequence.

 

  • Changing stars
  • Changing stars are stars that show sequential or random changes in their brightness due to their internal or external properties.

 

  • The Structure of the Stars
  • Stable, constantly within the star of the main sequence is a constant balance of forces against each other. The forces that balance each other are the inwardly directed gravitational force and the heat of the plasma gas that meets it. In order for these forces to balance each other, the temperature in a typical star’s core must be 107 K or higher. The temperature and pressure generated in the hydrogen-burning core of a main-sequence star produces enough energy to prevent nucleation and further star collapse.

 

  • The nuclei emit energy in the form of gamma rays as the star fuses in the nucleus. They interact with the plasma surrounding the photons and add heat to the nucleus. The stars on the main line turn the hydrogen helium and slowly but regularly increase the helium in the core. Eventually the helium rate is dominant and the energy production in the core stops. Instead, in stars larger than 0,4 solar mass, a core fusion occurs in the slowly expanding crust around the decayed helium nucleus.

 

  • Apart from the hydrostatic equilibrium, there is also a thermal equilibrium within the stable star that provides energy balance. As a result of the radial temperature gradient in the interior, an energy flow is continuously generated outward. The energy stream flowing outward from any layer of the star is exactly the flow of energy coming in from above.

 

  • The radiation region is the region of the star where the energy transfer is so efficient as to provide energy flow. In this region, the plasma is stationary and any mass movement is damped. If this is not the case, the plasma will still be unbalanced and heat transfer (convection) will take place to form the heat transfer zone. It occurs near the nucleus or in the areas of high-opacity of the outer layer where very high energy flows occur.

 

  • The occurrence of heat generation in the outer layers of the main array star depends on the type of spectrum. The stars, which are a few times the mass of the sun, have heat radiation in their interior and radiation areas in their outer layers. On the other hand, small stars such as the Sun are located in the outer layers. The red dwarf, which has less mass than the solar mass of 0.4, has a heat sink, so there is no helium accumulation in the nucleus. As the star of the star grows older and as the formation of the interior changes, the heat zones also change.

 

  • The part of the star of the main sequence visible to the observer is called the photoreceptor. In this layer, the star’s plasma gas becomes transparent to the light’s light (photons). The energy generated in the nucleus propagates far away from the light. Starlings or zones with low average temperatures appear in the light.

 

  • The lightbulb has a star gazeur (atmosphere) on it. In the main series stars like the sun, there is a thin color where the needles are found in the lowest level of the gas chamber and the starbursts begin. That’s 100 km. The environment of the transition zone in which the temperature has increased very rapidly. Beyond this, there is a solar crown, which is an overheated plasma that can reach millions of kilometers out. The formation of a crown depends on the formation of heat in the outer layers of the star. Despite a very high temperature, the crown radiates very little light. The sun‘s crown still appears only in the solar eclipse.

 

  • After the crow, a stellar wind of plasma particles spreads outward to interact with the interstellar medium.
Star
Author: wik Date: 1:52 pm

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