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The Big Bang Theory of how the universe began. Space started expanding/inflating
Hertzsprung-Russell (H-R) Diagram Plot of stars luminosity vs. their colour/temperature. Blue star = hot temperature. Red star = cool temperature
Luminosity The brightness of a star. How much energy it gives off.
Star A cloud of gas that is undergoing nuclear fusion reaction in the core.
Nuclear fusion A nuclear reaction that combines two Hydrogens into a He, for example. The process by which new elements are created.
Core of a star The centre part of a star that is dense and hot.
Main Sequence The evolution of most stars falls on the main sequence on the H-R diagram. Hot and bright stars eventually end up cool and dim.
Supernova A huge, energy-releasing explosion of stellar material from a star.
Red Giant A stage in stellar evolution towards the end of a star's life. The star has a very large radius and is relatively cool.
Red Dwarf A stage in stellar evolution towards the end of a star's life. The star is relatively small and cool./dim.
White Dwarf A stage in stellar evolution. The star is small and very hot/bright.
Black Hole A massive star ends up collapsing under its own gravity and forms a black hole, whose gravity is so enormous that nothing, not even light can escape.
Neutron Star A massive star ends up collapsing into a neutron star. All the electrons and protons combing into neutrons under the enormous gravity.
Nebula A giant cloud of gas and dust.
Sun A star that has planets revolving around it.
Planet A rocky or gaseous celestial body that is orbiting a star.
Solar System A sun and its planets/moons.
Phases of the moon The moon reflects varying amounts of the sun's light as it orbits around the earth .
New Moon The moon is between the earth and the sun and we do not see any reflected light.
Full Moon The earth is between the sun and the moon and we see all the reflected light from the sun.
Constellation A grouping of stars that we see in the night sky in the same location.
Aurora Borealis / Aurora Australis The Northern /Southern Lights. Particles from the sun ionize atoms and molecules in the atmosphere, giving off light in the process.
Electromagnetic Radiation Photon (particle of light) behaves as a wave with different frequencies/wavelenths. High frequency = high energy
Photon particle of light travelling at 300,000,000 km/s
Electromagnetic Spectrum The range of EM radiation from gramma rays (high energy) to radio waves (low energy)
Doppler effect The perceived change in frequency of a wave because the wave source is moving relative to the observer or vice versa.
Blue Shift The wave source is moving towards the observer (or vice versa) so the frequency of the wave appears to increase.
Red Shift The wave source is moving away from the observer (or vice versa) so the frequency of the wave appears to decrease.
Frequency of a wave How many times a wave is generated in one second.
Wavelength of a wave The distance from the crest of a wave to the next crest. Or trough to trough.
Speed of a wave The frequency of a wave times its wavelength is equal to its speed.
Winter Solstice/Summer Solstice The shortest (Dec 21) /longest(June 21) day of the year on earth.
Spring/Fall Equinox Two days of the year, March 21, September 21 where we have equal hours of day and night.
Astronomical Unit The distance from the earth to the sun - about 150,000,000 km
Lightyear The distance light can travel in one year - about 9.46 x 10^12 km
The age of the universe Approximately 14 billion years.
The age of the sun Approximately 4.5 billion years.
Inner Planets/Terrestrial Planets Venus, Mercury, Earth, Mars
Outer Planets/Jovian planets Jupiter, Saturn, Neptune,Uranus
Dark Matter/Dark Energy Proposed theory that 27% of the matter in the universe does not interact with EM radiation. 70% of universe is made up of dark energy.
Lunar Eclipse The earth passes in front of the full moon, blocking its reflected sunlight from reaching the earth.
Solar Eclipse The new moon passes in front of the sun blocking its sunlight from reaching the earth.
Sunspots Areas of magnetic fields on the sun
Solar flare Solar prominence that erupts sending solar material into space
Solar prominence Large loops of bright gas near sunspots
Corona The sun's outer atmosphere, visible during a solar eclipse.
Asteroid Chunks of rocky material, in various sizes, orbiting around the solar system.
Meteor Asteroid that enters the earth's atmosphere burning up due to friction. Also known as shooting star.
Meteorite Meteor that does not completely burn up in the earth's atmosphere and hits earth.
Kuiper belt Belt of icy, rocky chunks orbiting the sun outside of Neptune.
Oort Cloud A sphere of space dust and debris that extends to the very edge of the solar system.
Astronomy The study of stars, planets, galaxies.
Cosmology The study of the universe.
Created by: mkoulis



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