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Science 8
8.8A-B Components of the Universe
Term | Definition |
---|---|
Universe | all space and the matter space contains |
Star | a self-luminous celestial body consisting of a mass of gas help together by its own gravity in which the energy is generated by nuclear reactions in its interior |
Hertzsprung-Russell Diagram | a plot of the surface temperature (color) or stars vs. their luminosity (brightness) |
Luminosity | the intensity if light from a celestial body that can be used to identify the body's characteristics |
Main Sequence | stable stars in the middle development phases that ploy along a continuous diagonal belt on the H-R Diagram |
Nebula | large cloud of gas and dust in interstellar space; the location of star formation |
Supernova | the death of a large star by explosion |
Black Hole | the remains of a star or other large object that collapsed under its owe gravity to form a super dense object with gravity so strong light cannot escape irs pull |
Galaxy | a large grouping of stars in space |
Elliptical Galaxy | a galaxy with a ling oval shape, a bright center, no apparent internal structure or spiral arms, and very little dust or gas |
Spiral Galaxy | a galaxy with a bulge in the center and very distinct long arms winding around the center |
Lenticular Galaxy | galaxy with a central bulge or bar with short arms, if any present |
Irregular Galaxy | a galaxy with very little symmetry that does not fit into any category |
SUn | the luminous star, composed mainly of hydrogen and helium, around which other planets and Earth revolve |
Milky Way Galaxy | the galaxy in which the Sun and Earth are located |
Spiral Arms | streaming arcs of millions of stars swirling around the center of a spiral galaxy such as the Milky Way |
Galactic Center | rotation center of a galaxy |
Dust Lanes | bands of dust that appear as darks ribbons against the bright star in a galaxy |
Solar Mass | used in astronomy as a standard unit to compare the size of other stars with our Sun |
Speed of Light | how fast light travels (i.e. 300,00 km/s) |
Scale Model | a representation of an object that is accurate in its proportions to the actual object |