240 likes | 470 Views
Unit 5 Light years, Theories and Characteristics of the Universe. THEORY is: . An idea that is the best explanation of many observations and helps make new predictions. Light year is: . Distance that light travel in a vacuum in one year, about 9.5 trillion km- which is used to
E N D
Unit 5 Light years, Theories and Characteristics of the Universe
THEORY is: An idea that is the best explanation of many observations and helps make new predictions
Light year is: Distance that light travel in a vacuum in one year, about 9.5 trillion km- which is used to record distances between stars and galaxies
SPEED of LIGHT is: The speed at which light travels: About 186,282 miles per second or 299,792 kilometers per second TIME NOT DISTANCE !
BIG BANG THEORY is: A theory that states that about 12 billion to 15 billion years ago, the universe began with a huge, fiery explosion.
UNIVERSE is: the totality of everything thatexists,including all matter and energy, the planets, stars, galaxies, and the contents of intergalactic space.
Galaxy is: Large group of stars, dust and gas held together by gravity; can be elliptical, spiral, and irregular Irregular Galaxy
BLACK HOLE is: Final stage in the evolution of a supernova, in which the core’s mass collapses to a point that it has no volume and whose gravity is so strong that not even light can escape
STAR is: A huge object in space made up of gas and giving off light and heat from nuclear reactions; the sun is a star
MAIN SEQUENCE STAR is: A "main sequence star" is not really a type of star but a period in a stars life. When a star is in "main sequence" it is converting hydrogen into energy. This is the longest period in a stars lifetime.
STELLAR NEBULA is: is an interstellar cloud of dust, hydrogen, helium and other ionized gases. WHERE A STAR IS BORN!
PLANETARYNEBULA made up of gas and plasma, they are made by certain types of stars when they die.
Luminosity is: a measure of the radiant power emitted by a star.
Hertzsprung-Russell diagram a scatter graph of stars in which the absolute magnitude (intrinsic luminosity) of stars is plotted vertically against their surface temperature (or corresponding spectral types)
ABSOLUTE MAGNITUDE a measure of the star's luminosity---the total amount of energy radiated by the star every second.
APPARENT MAGNITUDE The apparent brightness of a star observed from the Earth
Electromagnetic Spectrum Full range of electromagnetic waves
TROUGH is: the lowest part of a wave; the part of a wave with the least magnitude.
CREST is: the highest part of a wave; the part of a wave with the greatest magnitude.
WAVELENGTH is: The distance between successive crests of a wave
FREQUENCY is: the number of occurrences of a repeating event per unit time.
NANOMETER is: 1 billionth of a meter, written 10⁻⁹ m
Hertz is: Measurement of wave frequency equal to vibrations per second
Spectroscope is: Instrument used for producing and observing spectra.