Science vocab chapter 9

  1. Milky Way
    • The galaxy that includes
    • the solar system; appears as a hazy white band in the night sky

    E.g. is a spiral galaxy
  2. Galaxy
    • A huge collection of stars,
    • planets, gas and dust that is held together by gravity

    E.g. we are located in the Milky Way galaxy
  3. Star cluster
    • A collection of stars held
    • together by gravity

    E.g. open clusters, globular clusters
  4. Open cluster
    • A collection of 50 to 1000
    • stars; open clusters appear along the main band of the Milky Way

    E.g. the plelades open star cluster
  5. Globular cluster
    • A collection of 100 000 to
    • a million stars in a distinctive spherical shape; globular clusters appear
    • around the centre of the Milky Way

    E.g. appear in the direction of constellations
  6. Local group
    • The small group of galaxies
    • that includes the Milky Way

    E.g. includes Andromeda and the pinwheel galaxies
  7. Supercluster
    • A gigantic cluster of 4 to
    • 25 galaxies, which is hundreds to millions of light years in size

    E.g. almost all galaxies arranged in clusters
  8. Shapes of galaxies
    • Galaxies come in different
    • shapes and sizes

    E.g. spiral, elliptical, irregular
  9. Cosmology
    The study of the universe

    E.g. cosmologists do this
  10. Doppler Effect
    • The change in frequency of
    • a light source due to its motion relative to an observer; also, the change in
    • pitch of a sound due to the motion of the source relative to an observer

    E.g. redshifting, blueshifting
  11. Redshift
    • The effect in which objects
    • moving away from an observer have their wavelengths lengthened, toward the red
    • end of the visible spectrum

    E.g. the universe is redshifting from the centre
  12. Blueshift
    • The effect in which objects
    • moving toward an observer have their wavelengths shortened, toward the blue end
    • of the visible spectrum
  13. Big bang
    • The event that may have
    • triggered the expansion of the universe 14 billion years ago

    E.g. evidence is CMB
  14. Cosmic microwave background
    (CMB) radiation
    • The radiation left over
    • from the big bang, which fills the universe

    E.g. started out as gamma rays
  15. Dark matter
    • The most abundant form of
    • matter in the universe; invisible to telescopes

    E.g. 90% of matter
  16. Dark energy
    • A form of energy that makes up nearly three quarters of the
    • universe; has the effect of increasing the expansion of the universe

    E.g. aka anti-gravity
Author
dilanf
ID
256812
Card Set
Science vocab chapter 9
Description
Science vocab chapter 9
Updated