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7. 
   ELLIPTIK GALAKTIKA- ELLIPTICAL GALAXY An elliptical galaxy is a galaxy having an approximately
   

ellipsoidal shape and a smooth, nearly featureless brightness profile. They range in shape from nearly spherical to highly flat and in size from hundreds of millions to over one trillion stars. They can be the result of two galaxies colliding.

Elliptical galaxies are one of the three main classes of galaxy originally described by American astronomer Edwin Hubble in his 1936 work The Realm of the Nebulae, along with spiral and lenticular galaxies. Elliptical galaxies are (together with lenticular galaxies) also called "early-type" galaxies (ETG), due to their location in the Hubble sequence.

7. 
   NOTO’G’RI GALAKTIKA- IRREGULARS Galaxies that do not fit into the Hubble sequence, because they
   

have no regular structure (either disk-like or ellipsoidal), are termed irregular galaxies. Hubble defined two classes of irregular galaxy:

Irr I galaxies have asymmetric profiles and lack a central bulge or obvious spiral structure; instead they contain many individual clusters of young stars

Irr II galaxies have smoother, asymmetric appearances and are not clearly resolved into individual stars or stellar clusters

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	In his extension to the Hubble sequence, de Vaucouleurs called the Irr I galaxies 'Magellanic irregulars', after the Magellanic Clouds - two satellites of the Milky Way which Hubble classified as Irr I. The discovery of a faint spiral structure[10] in the Large Magellanic Cloud led de Vaucouleurs to further divide the irregular galaxies into those that, like the LMC, show some evidence for spiral structure (these are given the symbol Sm) and those that have no obvious structure, such as the Small Magellanic Cloud (denoted Im). In the extended Hubble sequence, the Magellanic irregulars are usually placed at the end of the spiral branch of the Hubble tuning fork.
9.	GALAKTIKA DISKI- DISC (GALAXY) A disc is a component of disc galaxies, such as spiral galaxies, or lenticular galaxies. The galactic disc is the plane in which the spirals, bars and discs of disc galaxies exist. Galaxy discs tend to have more gas and dust, and younger stars than galactic bulges, or galactic haloes. The galactic disc is mainly composed of gas, dust and stars. The gas and dust component of the galactic disk is called the gaseous disk. The star component of the galactic disk is called the stellar disk
10.	ASTRONOMIYA-ASTRONOMY Astronomy is a natural science that deals with the study of celestial objects (such as stars, planets, comets, nebulae, star clusters and galaxies) and phenomena that originate outside the Earth's atmosphere (such as the cosmic background radiation). It is concerned with the evolution, physics, chemistry, meteorology, and motion of celestial objects, as well as the formation and development of the universe.
11.	YULDUZ-STAR A star is a massive, luminous ball of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth. Other stars are visible from Earth during the night when they are not outshone by the Sun or blocked by atmospheric phenomena. Historically, the most prominent stars on the celestial sphere were grouped together into constellations and asterisms, and the brightest stars gained proper names. Extensive catalogues of stars have been assembled by astronomers, which provide standardized star designations.
12.	QO‘SHALOQ YULDUZ - DOUBLE STAR A binary star is a star system consisting of two stars orbiting around their common center of mass. The brighter star is called the primary and the other is its companion star, comes, or secondary. Research between the early 19th century and today suggests that many stars are part of either binary star systems or star systems with more than two stars, called multiple star systems. The term double star may

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	be used synonymously with binary star, but more generally, a double star may be either a binary star or an optical double star which consists of two stars with no physical connection but which appear close together in the sky as seen from the Earth. A double star may be determined to be optical if its components have sufficiently different proper motions or radial velocities, or if parallax measurements reveal its two components to be at sufficiently different distances from the Earth. Most known double stars have not yet been determined to be either bound binary star systems or optical doubles.
13.	MASSIV YULDUZ - MASSIVE STARS During their helium-burning phase, very high mass stars with more than nine solar masses expand to form red supergiants. Once this fuel is exhausted at the core, they can continue to fuse elements heavier than helium. The core contracts until the temperature and pressure are sufficient to fuse carbon (see carbon burning process). This process continues, with the successive stages being fueled by neon (see neon burning process), oxygen (see oxygen burning process), and silicon (see silicon burning process). Near the end of the star's life, fusion can occur along a series of onion-layer shells within the star. Each shell fuses a different element, with the outermost shell fusing hydrogen; the next shell fusing helium, and so forth. The final stage is reached when the star begins producing iron. Since iron nuclei are more tightly bound than any heavier nuclei, if they are fused they do not release energy—the process would, on the contrary, consume energy. Likewise, since they are more tightly bound than all lighter nuclei, energy cannot be released by fission. In relatively old, very massive stars, a large core of inert iron will accumulate in the center of the star. The heavier elements in these stars can work their way up to the surface, forming evolved objects known as Wolf-Rayet stars that have a dense stellar wind which sheds the outer atmosphere.
14.	CHANG - COLLAPSE An evolved, average-size star will now shed its outer layers as a planetary nebula. If what remains after the outer atmosphere has been shed is less than 1.4 solar masses, it shrinks to a relatively tiny object (about the size of Earth) that is not massive enough for further compression to take place, known as a white dwarf. The electron- degenerate matter inside a white dwarf is no longer a plasma, even though stars are generally referred to as being spheres of plasma. White dwarfs will eventually fade into black dwarfs over a very long stretch of time. The Crab Nebula, remnants of a supernova that was first observed around 1050 AD In larger stars, fusion continues until the iron core has grown so

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	large (more than 1.4 solar masses) that it can no longer support its own mass. This core will suddenly collapse as its electrons are driven into its protons, forming neutrons and neutrinos in a burst of inverse beta decay, or electron capture. The shockwave formed by this sudden collapse causes the rest of the star to explode in a supernova. Supernovae are so bright that they may briefly outshine the star's entire home galaxy. When they occur within the Milky Way, supernovae have historically been observed by naked-eye observers as "new stars" where none existed before.
15.	SPEKTR- SPECTR Astronomical spectroscopy is the technique of spectroscopy used in astronomy. The object of study is the spectrum of electromagnetic radiation, including visible light, which radiates from stars and other celestial objects. Spectroscopy can be used to derive many properties of distant stars and galaxies, such as their chemical composition, but also their motion by Doppler shift measurements.
16.	SPEKTRASKOP - SPECTROSCOPY Spectroscopy is the study of the interaction between matter and radiated energy. Historically, spectroscopy originated through the study of visible light dispersed according to its wavelength, e.g., by a prism. Later the concept was expanded greatly to comprise any interaction with radiative energy as a function of its wavelength or frequency. Spectroscopic data is often represented by a spectrum, a plot of the response of interest as a function of wavelength or frequency. Spectrometry and spectrography are terms used to refer to the measurement of radiation intensity as a function of wavelength and are often used to describe experimental spectroscopic methods. Spectral measurement devices are referred to as spectrometers, spectrophotometers, spectrographs or spectral analyzers.
17.	OSMON-THE SKY he sky is the part of the atmosphere or outer space visible from the surface of any astronomical object. It is difficult to define precisely for several reasons. During daylight, the sky of Earth has the appearance of a pale blue surface because the air scatters the sunlight. The sky is sometimes defined as the denser gaseous zone of a planet's atmosphere. At night the sky has the appearance of a black surface or region scattered with stars.
18.	QUYOSH- SUN The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields. It has a diameter of about 1,392,000 km, about 109 times that of Earth, and its mass (about 2x1030 kilograms, 330,000 times that of Earth) accounts for about 99.86% of the total mass of the Solar System. Chemically, about three quarters of the Sun's mass consists of hydrogen,

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	while the rest is mostly helium. Less than 2% consists of heavier elements, including oxygen, carbon, neon, iron, and others.
19.	ATOM- ATOMS Atomic spectroscopy was the first application of spectroscopy developed. Atomic absorption spectroscopy (AAS) and atomic emission spectroscopy (AES) involve visible and ultraviolet light. These absorptions and emissions, often referred to as atomic spectral lines, are due to electronic transitions of an outer shell electron to an excited state. Atoms also have distinct x-ray spectra that are attributable to the excitation of inner shell electrons to excited states. Atoms of different elements have distinct spectra and therefore atomic spectroscopy allows for the identification and quantitation of a sample's elemental composition. Robert Bunsen, developer of the Bunsen burner, and Gustav Kirchhoff discovered new elements by observing their emission spectra. Atomic absorption lines are observed in the solar spectrum and referred to as Fraunhofer lines after their discoverer. A comprehensive explanation of the hydrogen spectrum was an early success of quantum mechanics and explaining the Lamb shift observed in the hydrogen spectrum led to the development of quantum electrodynamics.
20.	YER- THE EARTH Earth (or the Earth) is the third planet from the Sun and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets. It is sometimes referred to as the World, the Blue Planet,[ or by its Latin name, Terra. Home to millions of species including humans, Earth is currently the only astronomical body where life is known to exist. The planet formed 4.54 billion years ago, and life appeared on its surface within one billion years.Earth's biosphere has significantly altered the atmosphere and other abiotic conditions on the planet, enabling the proliferation of aerobic organisms as well as the formation of the ozone layer which, together with Earth's magnetic field, blocks harmful solar radiation, permitting life on land. The physical properties of the Earth, as well as its geological history and orbit, have allowed life to persist during this period. The planet is expected to continue supporting life for at least another 500 million years.
21.	KOINOT- THE UNIVERSE everything that exists, including all physical matter and energy, the planets, stars, galaxies, and the contents of intergalactic space, although this usage may differ with the context (see definitions, below). The term universe may be used in slightly different contextual senses, denoting such concepts as the cosmos, the world, or nature. Observations of earlier stages in the development of the universe, which can be seen at great distances, suggest that the universe has been governed by the same

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	physical laws and constants throughout most of its extent and history.
22.	TEMPERATURA- TEMPERATURE Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot. Quantitatively, temperature is measured with thermometers, which may be calibrated to a variety of temperature scales. Much of the world uses the Celsius scale (°C) for most temperature measurements. It has the same incremental scaling as the Kelvin scale used by scientists, but fixes its null point, at 0°C = 273.15K, the freezing point of water.[note 1] A few countries, most notably the United States, use the Fahrenheit scale for common purposes, a historical scale on which water freezes at 32 °F and boils at 212 °F. For practical purposes of scientific temperature measurement, the International System of Units (SI) defines a scale and unit for the thermodynamic temperature by using the easily reproducible temperature of the triple point of water as a second reference point. For historical reasons, the triple point is fixed at 273.16 units of the measurement increment, which has been named the kelvin in honor of the Scottish physicist who first defined the scale. The unit symbol of the kelvin is K.
23.	QORA JISM- A BLACK BODY A black body is an idealized physical body that absorbs all incident electromagnetic radiation. Because of this perfect absorptivity at all wavelengths, a black body is also the best possible emitter of thermal radiation, which it radiates incandescently in a characteristic, continuous spectrum that depends on the body's temperature. At Earth- ambient temperatures this emission is in the infrared region of the electromagnetic spectrum and is not visible. The object appears black, since it does not reflect or emit any visible light.
24.	MASSA- WEIGHT In most physics textbooks, weight is the name given to the force on an object due to gravity. However, some books use an operational definition, defining the weight of an object as the force measured by the operation of weighing it (that is, the force required to support it). Both definitions imply that weight is a force and that its value depends on the local gravitational field. For example, an object with a mass of one kilogram will have a weight of 9.8 newtons on the surface of the Earth, about one-sixth as much on the Moon, and zero when floating freely far out in space away from all gravitational influence. The differences between the two definitions are discussed below. For example, they differ over the weight of an object in free fall, such as a falling apple or

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	an astronaut in an orbiting spacecraft. In these cases, the operational definition implies the weight is zero, whereas the gravitational definition does not.
25.	MAGNIT MAYDON - MAGNETIC FIELD Magnetic field of a star is generated within regions of the interior where convective circulation occurs. This movement of conductive plasma functions like a dynamo, generating magnetic fields that extend throughout the star. The strength of the magnetic field varies with the mass and composition of the star, and the amount of magnetic surface activity depends upon the star's rate of rotation. This surface activity produces starspots, which are regions of strong magnetic fields and lower than normal surface temperatures. Coronal loops are arching magnetic fields that reach out into the corona from active regions. Stellar flares are bursts of high-energy particles that are emitted due to the same magnetic activity.
26.	TELESKOP- TELESCOPE A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation (such as visible light). The first known practical telescopes were invented in the Netherlands at the beginning of the 17th century. The word telescope can refer to a wide range of instruments detecting different regions of the electromagnetic spectrum. The word "telescope" (from the Greek xp^s, tele "far" and aKonsTv, skopein "to look or see"; xn^saKono^, teleskopos "far-seeing") was coined in 1611 by the Greek mathematician Giovanni Demisiani for one of Galileo Galilei's instruments presented at a banquet at the Accademia dei Lincei. In the Starry Messenger Galileo had used the term "perspicillum".
27.	ORBITA- ORBIT In physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet around the center of a star system, such as the solar system. Orbits of planets are typically elliptical. Current understanding of the mechanics of orbital motion is based on Albert Einstein's general theory of relativity, which accounts for gravity as due to curvature of space-time, with orbits following geodesics; though in common practice an approximate force-based theory of universal gravitation based on Kepler's laws of planetary mot
28.	RADIUS- RADIUS Remote Authentication Dial In User Service (RADIUS) is a networking protocol that provides centralized Authentication, Authorization, and Accounting (AAA) management for computers to connect and use a network service. RADIUS was developed by Livingston Enterprises, Inc., in 1991 as an access server authentication

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	and accounting protocol and later brought into the Internet Engineering Task Force (IETF) standards. Because of the broad support and the ubiquitous nature of the RADIUS protocol, it is often used by ISPs and enterprises to manage access to the Internet or internal networks, wireless networks, and integrated e-mail services. These networks may incorporate modems, DSL, access points, VPNs, network ports, web servers, etc.
29.	TORTISHISH-GRAVITATION Gravitation is a natural phenomenon by which physical bodies attract with a force proportional to their mass. In everyday life, gravitation is most familiar as the agent that gives weight to objects with mass and causes them to fall to the ground when dropped. Gravitation causes dispersed matter to coalesce, and coalesced matter to remain intact, thus accounting for the existence of the Earth, the Sun, and most of the macroscopic objects in the universe. Gravitation is responsible for keeping the Earth and the other planets in their orbits around the Sun; for keeping the Moon in its orbit around the Earth; for the formation of tides; for natural convection, by which fluid flow occurs under the influence of a density gradient and gravity; for heating the interiors of forming stars and planets to very high temperatures; and for various other phenomena observed on Earth.
30.	AERODINAMIK KUCH-AERODYNAMIC FORCE Aerodynamic force is the resultant force exerted on a body by the air (or some other gas) in which the body is immersed, and is due to the relative motion between the body and the fluid. An aerodynamic force arises from two causes: the force due to the pressure on the surface of the body the force due to viscosity, also known as skin friction When a body is exposed to the wind it experiences a force in the direction in which the wind is moving. This is an aerodynamic force. When a body is moving in air or some other gas the aerodynamic force is usually called drag.
31.	BOSIM KUCHI-PRESSURE-GRADIENT FORCE The pressure gradient force is not actually a 'force' but the acceleration of air due to pressure difference (a force per unit mass). It is usually responsible for accelerating a parcel of air from a high atmospheric pressure region to a low pressure region, resulting in wind. In meteorology, pressure gradient force refers to the horizontal movement of air according to the equation The term F / m is equal to the acceleration dv / dt because this is an expression of Newton's law F = ma. dp / dx is the component of the pressure gradient along the x-axis. p is the mass density and (1 / p) shows that as the mass density increases, the acceleration due to the pressure gradient becomes smaller.

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32.	MAGNIT KUCHLARI-FORCE BETWEEN MAGNETS Magnets exert forces and torques on each other due to the complex rules of electromagnetism. The magnetic field of magnets are due to microscopic currents of electrically charged electrons orbiting nuclei and the intrinsic magnetism of fundamental particles (such as electrons) that make up the material. Both of these are modeled quite well as tiny loops of current called magnetic dipoles that produce their own magnetic field and are affected by external magnetic fields. The most elementary force between magnets, therefore, is the magnetic dipole- dipole interaction. If all of the magnetic dipoles that make up two magnets are known then the net force on both magnets can be determined by summing up all these interaction between the dipoles of the first magnet and that of the second. It is often more convenient to model the force between two magnets as being due to forces between magnetic poles having magnetic charges 'smeared' over them. Such a model fails to account for many important properties of magnetism such as the relationship between angular momentum and magnetic dipoles. Further, magnetic charge does not exist. This model works quite well, though, in predicting the forces between simple magnets where good models of how the 'magnetic charge' is distributed is available.
33.	KOSMIK FAZO-SPACE PHASE n mathematics and physics, a phase space, introduced by Willard Gibbs in 1901,[1] is a space in which all possible states of a system are represented, with each possible state of the system corresponding to one unique point in the phase space. For mechanical systems, the phase space usually consists of all possible values of position and momentum variables. A plot of position and momentum variables as a function of time is sometimes called a phase plot or a phase diagram. Phase diagram, however, is more usually reserved in the physical sciences for a diagram showing the various regions of stability of the thermodynamic phases of a chemical system, which consists of pressure, temperature, and composition.
34.	ENERGIYA INTEGRALI- INTEGRAL OF ENERGY Integral Energy is the second largest state-owned energy corporation in New South Wales, incorporated under the Energy Services Corporations Act 1995 from a merger between Prospect Electricity and Illawarra Electricity. Integral Energy is involved in electricity retail in addition to owning an electricity distribution network and currently holds licences to retail electricity in the contestable markets covered by the NEM (National Electricity Market). Integral Energy distributes and retails electricity and services to 807,000 customers, or 2.1 million people. The company is increasingly

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	operating outside of New South Wales, with the introduction of full retail contestability in other states. In addition to electricity retailing, Integral Energy also owns an electricity distribution network spanning 24,500 square kilometres in Greater Western Sydney, the Illawarra, and the Southern Highlands.
35.	IKKI JISM MASALASI- TWO-BODY PROBLEM determine the motion of two point particles that interact only with each other. Common examples include a satellite orbiting a planet, a planet orbiting a star, two stars orbiting each other (a binary star), and a classical electron orbiting an atomic nucleus (although to solve this system correctly a quantum mechanical approach must be used). The two-body problem can be re-formulated as two independent one-body problems, a trivial one and one that involves solving for the motion of one particle in an external potential. Since many one-body problems can be solved exactly, the corresponding two-body problem can also be solved. By contrast, the three-body problem (and, more generally, the n-body problem for n > 3) cannot be solved, except in special cases.
36.	AYLANISH DAVRI- THE ROTATION PERIOD of an astronomical object is the time it takes to complete one revolution around its axis of rotation relative to the background stars. It differs from the planet's solar day, which includes an extra fractional rotation needed to accommodate the portion of the planet's orbital period during one day.
37.	GIPERBOLIK TROEKTORIYA- HYPERBOLIC TRAJECTORY In astrodynamics or celestial mechanics a hyperbolic trajectory is a Kepler orbit with the eccentricity greater than 1. Under standard assumptions a body traveling along this trajectory will coast to infinity, arriving there with hyperbolic excess velocity relative to the central body. Similarly to parabolic trajectory all hyperbolic trajectories are also escape trajectories. The specific energy of a hyperbolic trajectory orbit is positive.
38.	ORBITA ELEMENTLARI- ORBITAL ELEMENTS A Kepler orbit is specified by six orbital elements, normally the following (assuming an elliptical orbit; parabolas and hyperbolas are also possible if eccentricity >= 1). Two define the shape and size of the ellipse: Eccentricity (e) Semimajor axis (a) Two define the orientation of the orbital plane: Inclination (j) Longitude of the ascending node (П) And finally: Argument of periapsis (a/) defines the orientation of the ellipse in

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	the orbital plane. Mean anomaly at epoch (defines the position of the orbiting body along the ellipse. (True anomaly (y) is shown on the diagram, since mean anomaly does not represent a real geometric angle.)
39.	HARAKAT-ROTATION A three-dimensional object rotates always around an imaginary line called a rotation axis.If the axis is within the body, and passes through its center of mass the body is said to rotate upon itself, or spin. A rotation about an external point, e.g. the Earth about the Sun, is called a revolution or orbital revolution, typically when it is produced by gravity.
40.	HARAKAT DINAMIKASI-FLIGHT DYNAMICS Flight dynamics is the science of air vehicle orientation and control in three dimensions. The three critical flight dynamics parameters are the angles of rotation in three dimensions about the vehicle's center of mass, known as pitch, roll and yaw (quite different from their use as Tait-Bryan angles).
41.	ENERGIYA-ENERGY In physics, energy (Ancient Greek: evepysia energeia "activity, operation"[1]) is an indirectly observed quantity. It is often understood as the ability a physical system has to do work on other physical systems.[2][3] Since work is defined as a force acting through a distance (a length of space), energy is always equivalent to the ability to exert pulls or pushes against the basic forces of nature, along a path of a certain length.
42.	ZARRA OQIMI- PARTICLE BEAMS Electron beams are used in welding, which allows energy densities up to 107 Wcm-2 across a narrow focus diameter of 0.1-1.3 mm and usually does not require a filler material. This welding technique must be performed in a vacuum, so that the electron beam does not interact with the gas prior to reaching the target, and it can be used to join conductive materials that would otherwise be considered unsuitable for welding. Electron beam lithography (EBL) is a method of etching semiconductors at resolutions smaller than a micron. This technique is limited by high costs, slow performance, the need to operate the beam in the vacuum and the tendency of the electrons to scatter in solids. The last problem limits the resolution to about 10 nm. For this reason, EBL is primarily used for the production of small numbers of specialized integrated circuits
43.	MAGNIT MAYDON - MAGNETIC FIELD magnetic field of a star is generated within regions of the interior where convective circulation occurs. This movement of conductive plasma functions like a dynamo, generating magnetic fields that extend throughout the star. The strength of the magnetic field varies with the

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	mass and composition of the star, and the amount of magnetic surface activity depends upon the star's rate of rotation. This surface activity produces starspots, which are regions of strong magnetic fields and lower than normal surface temperatures. Coronal loops are arching magnetic fields that reach out into the corona from active regions. Stellar flares are bursts of high-energy particles that are emitted due to the same magnetic activity.
44.	TELESKOP- TELESCOPE A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation (such as visible light). The first known practical telescopes were invented in the Netherlands at the beginning of the 17th century. The word telescope can refer to a wide range of instruments detecting different regions of the electromagnetic spectrum. The word "telescope" (from the Greek rpXs, tele "far" and aKonsiv, skopein "to look or see"; TpXsaKono^, teleskopos "far-seeing") was coined in 1611 by the Greek mathematician Giovanni Demisiani for one of Galileo Galilei's instruments presented at a banquet at the Accademia dei Lincei. In the Starry Messenger Galileo had used the term "perspicillum".
45.	RADIO TELESKOP - RADIO TELESCOPES Nanfay Radioheliographe is an interferometer composed of 48 antennas observing at meter-decimeter wavelengths. The radioheliographe is installed at the Nanfay Radio Observatory (France). Owens Valley Solar Array is a radio interferometer operated by New Jersey Institute of Technology consisting of 7 antenas observing from 1 to 18 GHz in both left and right circular polarization. OVSA is located in Owens Valley, California, (USA), now is under reform, increasing to 15 the total number of antennas and upgrading its control system.
46.	KOSMIK TELESKOP - SPACE TELESCOPES Space Telescopes The following spacecraft missions have flares as their main observation target. Yohkoh - The Yohkoh (originally Solar A) spacecraft observed the Sun with a variety of instruments from its launch in 1991 until its failure in 2001. The observations spanned a period from one solar maximum to the next. Two instruments of particular use for flare observations were the Soft X-ray Telescope (SXT), a glancing incidence low energy X-ray telescope for photon energies of order 1 keV, and the Hard X-ray Telescope (HXT), a collimation counting instrument which produced images in higher energy X-rays (15-92 keV) by image synthesis.
47.	YULDUZ ATMOSFERASI - STELLAR ATMOSPHERE The stellar atmosphere is the outer region of the volume of a star,

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	lying above the stellar core, radiation zone and convection zone. It is divided into several regions of distinct character: The photosphere, which is the atmosphere's lowest and coolest layer is normally its only visible part. Light escaping from the surface of the star stems from this region and passes through the higher layers. The Sun's photosphere has a temperature in the 5,770 K to 5,780 K range. Starspots, cool regions of disrupted magnetic field lie on the photosphere. Above the photosphere lies the chromosphere. This part of the atmosphere first cools down and then starts to heat up to about 10 times the temperature of the photosphere. Above the chromosphere lies the transition region, where the temperature increases rapidly on a distance of only around 100 km.
48.	NURIY TEZLIK- LIGHT SPEED The speed of light (meaning speed of light in vacuum), usually denoted by c, is a physical constant important in many areas of physics. Its value is 299,792,458 metres per second, a figure that is exact since the length of the metre is defined from this constant and the international standard for time. This speed is approximately 186,282 miles per second. It is the maximum speed at which all energy, matter, and information in the universe can travel. It is the speed of all massless particles and associated fields—including electromagnetic radiation such as light—in vacuum, and it is predicted by the current theory to be the speed of gravity (that is, gravitational waves). Such particles and waves travel at c regardless of the motion of the source or the inertial frame of reference of the observer. In the theory of relativity, c interrelates space and time, and appears in the famous equation of mass-energy equivalence E = mc2.
49.	KIMYOVIY TARKIBI- CHEMICAL COMPOSITION In astronomy and physical cosmology, the metallicity of an object is the proportion of its matter made up of chemical elements other than hydrogen and helium. Since stars, which comprise most of the visible matter in the universe, are composed mostly of hydrogen and helium, astronomers use for convenience the blanket term "metal" to describe all other elements collectively. Thus, a nebula rich in carbon, nitrogen, oxygen, and neon would be "metal-rich" in astrophysical terms even though those elements are non-metals in chemistry. This term should not be confused with the usual definition of "metal"; metallic bonds are impossible within stars, and the very strongest chemical bonds are only possible in the outer layers of cool K and M stars. Normal chemistry therefore has little or no relevance in stellar interiors.
50.	MASSIV YULDUZ - MASSIVE STARS During their helium-burning phase, very high mass stars with more than nine solar masses expand to form red supergiants. Once this fuel is

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exhausted at the core, they can continue to fuse elements heavier than helium.

The core contracts until the temperature and pressure are sufficient to fuse carbon (see carbon burning process). This process continues, with the successive stages being fueled by neon (see neon burning process), oxygen (see oxygen burning process), and silicon (see silicon burning process).

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