what are the three basic parts of a spiral galaxy?
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Spiral galaxies have three main components: a bulge, disk, and halo (see right). The bulge is a spherical structure found in the center of the galaxy. This feature mostly contains older stars. The disk is made up of dust, gas, and younger stars.
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['Baryonic Matter: ~5% of the mass in the universe. This is ordinary matter composed of protons, neutrons, and electrons. ... ', 'Cold Dark Matter: ~25% This is the so-called "missing mass" of the universe. ... ', 'Dark Energy: ~70%']
37641
There are four main categories of galaxies: elliptical, spiral, barred spiral, and irregular. These types of galaxies are further divided into subcategories while at the same time other types of galaxies exist based on their size and other unique features.
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['step one(4) -The solar nebula consisted of. -hydrogen, ... ', 'step two(2) -A disturbance. ... ', 'step three(2) -The solar nebula assumed a flat, disk shape. ... ', 'step four(2) -Inner planets began to form from metallic. ... ', 'step five(2) -Larger outer planets began forming from fragments.']
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The main part of the Sun has three layers: the core, the radiative zone, and the convection zone. The Sun's atmosphere also has three layers: the photosphere, the chromosphere, and the corona.
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['The Circle.', 'The Triangle.', 'The Rectangle.', 'The Rhombus.', 'The Square.', 'The Trapezoid.']
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The Milky Way has four main spiral arms: the Norma and Cygnus arm, Sagittarius, Scutum-Crux, and Perseus. The Sun is located in a minor arm, or spur, named the Orion Spur. The galactic disk itself is about 100,000 light years across, and the bar at the center is estimated to be about 27,000 light years long.
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The directory of observable objects in the universe is vast. The smallest components are atomic particles followed by atoms (mostly free hydrogen and helium), molecules, dust, space rocks, comets, asteroids, moons, dwarf planets, planets, solar systems, stars, black holes, nebulae, and galaxies.
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Elliptical galaxies contain primarily old stars, and do not have much gas and dust. There is very little new star formation in these galaxies. Irregular galaxies have no particular shape. They are among the smallest galaxies and they contain a vast amount of gas and dust.
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The three major components of the Milky Way are referred to as the disk, bulge, and the halo.
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Types of Galaxies Astronomers classify galaxies into three major categories: elliptical, spiral and irregular. These galaxies span a wide range of sizes, from dwarf galaxies containing as few as 100 million stars to giant galaxies with more than a trillion stars.
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A cell consists of three parts: the cell membrane, the nucleus, and, between the two, the cytoplasm.
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['Atmosphere - gas.', 'Hydrosphere - water.', 'Lithosphere - minerals.', 'Biosphere - life.']
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A galaxy is a system of solar systems and other stars. ... The galaxy that contains the Earth and its solar system is called the Milky Way. This galaxy is thought to contain more than 200 billion different stars. Solar systems orbit around their galaxies just as planets orbit around their suns.
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['The Sun. At the centre of the solar system lies the Sun. ... ', 'Planets and their satellites. ... ', 'Asteroids, meteoroids, comets, and interplanetary dust. ... ', 'Origin of the solar system. ... ', 'Extrasolar planetary systems. ... ', 'Main-sequence structure of the stars. ... ', 'The end states of stars. ... ', 'The evolution of stars.']
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The three parts of the geosphere are the crust, the mantle, and the core.
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A galaxy is a huge collection of gas, dust, and billions of stars and their solar systems. A galaxy is held together by gravity. Our galaxy, the Milky Way, also has a supermassive black hole in the middle. ... Some scientists think there could be as many as one hundred billion galaxies in the universe.