Beyond the solar system

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Made this when I was 12 for my group's report about astronomy. A presentation about Astronomy--Stars, Galaxies, Constellations, etc. I don't really see the point in just keeping it unused in my computer...

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Beyond the solar system

  1. 1. Beyond the SolarBeyond the Solar SystemSystem By: Group 2By: Group 2
  2. 2. AstronomyAstronomy Astronomy is the study of the night sky- from planets and moons to the stars and galaxies. Shortly, astronomy is the study of space and heavenly bodies. Astronomy is the most ancient of all sciences, dating back tens of thousands of years. It came from the Greek words astro meaning ‘star’ and nomia meaning law.
  3. 3. AstronomersAstronomers Astronomers are the people who engage in astronomy. They use telescopes to study objects far fainter and smaller that cannot be seen with the naked eye. Most astronomers work in observatories far from city lights, where they can get a very clear view of the sky.
  4. 4. Telescope and ObservatoryTelescope and Observatory
  5. 5. GalaxiesGalaxies Billions of nebulae or external galaxies make up the universe, which is believed to be an infinitely old and large super system. Galaxies are giant groups of millions or even trillions of stars. Our own galaxy is the Milky Way. There may be 20 trillion galaxies in the universe.
  6. 6. Only three galaxies are visible to the naked eye from the Earth besides the Milky Way – the Large and Small Magellanic Clouds, and the Andromeda galaxy. Although galaxies are vast, they are so far away that they look like fuzzy clouds. Only in 1916 did astronomers realize that they are huge star groups.
  7. 7. Classification of GalaxiesClassification of Galaxies As classified by astronomer Edwin Hubble, there are three basic types of galaxies- spiral, barred spiral, and elliptical. Another type, which is considered rare, is the irregular galaxy.
  8. 8. Spiral GalaxySpiral Galaxy • A spiral galaxy consists of a dense core at the center surrounded by a flat disk, a corona, and curved, spiraling arms. It includes both old and young stars. Spiral galaxies range in diameter from 20,000 to more than 100,000 light-years. About 80% of galaxies are of the spiral type.
  9. 9. Spiral GalaxySpiral Galaxy
  10. 10. Barred Spiral GalaxyBarred Spiral Galaxy • A barred spiral galaxy consists of a long bar of individual stars that passes through the central region of the galaxy. Spiral arms appear to extend from the ends of the bar. Barred spiral galaxies are named based on their general appearance.
  11. 11. Barred Spiral GalaxyBarred Spiral Galaxy
  12. 12. Elliptical GalaxyElliptical Galaxy • An elliptical galaxy is vast and very old, it is the most common of all galaxies. It is egg-shaped and has a smooth and round appearance. It is made up of as many as a trillion stars, therefore it has great mass.
  13. 13. Elliptical GalaxyElliptical Galaxy
  14. 14. Irregular GalaxyIrregular Galaxy Irregular galaxies are galaxies with no obvious shape. They may have been formed from the debris of galaxies that crashed into each other. It is full of young stars.
  15. 15. Irregular GalaxyIrregular Galaxy
  16. 16. StarsStars • Stars are huge balls of hydrogen and helium gas. It appears only like a tiny dot in the sky because of its great distance from the Earth. Stars twinkle because the air above the Earth’s surface is always in motion and the layers of the atmosphere have different densities.
  17. 17. Properties of StarsProperties of Stars Stars vary in brightness depending on their size, temperature, and distance from the Earth.
  18. 18. Color and Temperature • The color of a star depends on its size and temperature. Young stars are blue white or white in color. They have extremely high temperature. Old stars are red in color and have low surface temperature. The sun is a yellow star and has moderate surface temperature compared to blue white or white and red stars.
  19. 19. Temperature of Stars According to ColorTemperature of Stars According to Color Color Temperature White and Blue White 30, 000 to 60,000 F Yellow 10’000 F Orange 6,000 to 8,000 F Red 3,000 to 6,000 F
  20. 20. SizeSize • The size and brightness of a star depends on its mass – that is, how much gas is made of. Stars vary in size. A star may be a super giant, a giant, or a dwarf.
  21. 21. DistanceDistance • The average distance between the Earth and the sun is about 150 million kilometers. The value is equivalent to one astronomical unit (AU). Another unit that can be used to express distances in outer space is the light-year. This is the distance traveled by light ate the speed of 300,000 kilometers per second in one year. One light year is equivalent to about 9.6 million kilometers.
  22. 22. BrightnessBrightness • The measure of a star’s brightness is called magnitude. The brightest stars are classified as first-magnitude stars. Stars beyond the sixth magnitude can only be seen with a telescope. Some stars undergo regular periods or phases of brightness and dimness. Such stars are called variables. They expand and contract, causing their light to pulsate.
  23. 23. Evolution of StarsEvolution of Stars • Stars evolve from the hydrogen gases found in interstellar mediums called nebulae. Through the process of contraction, the temperature rises sufficiently to transform hydrogen gas present in the mass of to helium. The hot ball begins to glow brightly and gives rise to a protostar.
  24. 24. Equilibrium in StarsEquilibrium in Stars • The sun and majority of stars are in a state of equilibrium. There is a mutual gravitational attraction between the masses of forces that tend to collapse the star towards the core. The gravitational force must be in equilibrium with its internal force as shown by the fact that stars, like the sun, have remained more or less the same for billions of years.
  25. 25. ConstellationsConstellations • Hundreds or thousands of associated stars are called star clusters. Star clusters that are arranged in a definite pattern form a constellation. Earth’s revolution around the sun enables people to see different constellations in the sky at different times of the year. Constellations such as Ursa Minor, Ursa Major, Draco and Cassiopeia are always visible around the North Star.
  26. 26. The North StarThe North Star • The North Star, also known as Polaris, is located above the North Pole. It was first noticed by William Herschel in 1780. As seen through the Hubble Space Telescope, it lies in the handle of Ursa Minor. Travelers usually make Polaris as their guiding star as it helps them in determining direction. It is very close to North Celestial Pole, making it a North Pole Star
  27. 27. • You will notice that constellation are usually named after mythical gods, legendary heroes, and animals. These names were given to the star patterns, because their arrangements in the sky outline the shapes of animals, heroes and gods.
  28. 28. ConstellariumConstellarium • A constellarium is a device that projects the outlines of the constellations on surfaces, such as ceilings and walls.

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