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Star Cycle Vocab
Term | Definition |
---|---|
Life Cycle of a Star | The sequence of changes that occur in a star as it ages. |
Interstellar Medium | A thinly spread area of gas and dust. Gas is mainly hydrogen. Dust is mainly carbon and silicon. |
Nebula | Interstellar Medium begins to collect into big clouds. |
Protostar | Inside the nebula are greater and lesser gravity, causing the dust and gas to pull together. |
Equilibrium | A battle between gravity and gas pressure. |
Star | Formed by nuclear fusion process. Very hot ball of gas with hydrogen fusing with helium at the core. |
Main Sequence | Phase the stars live in. Stars spend most of their lives in this phase. |
Red Giant | Type of star. |
Planetary Nebula | A type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives |
White Dwarf | a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense. Doesn't have much volume. |
Black Dwarf | A theoretical stellar remnant, specifically a white dwarf that has cooled sufficiently that it no longer emits significant heat or light. |
Red Super Giants | stars with a supergiant luminosity class (Yerkes class I) of spectral type K or M. They are the largest stars in the universe by volume. |
Black Hole | a region of spacetime where gravity is so strong that nothing, even light, can escape from it. |
Hertzsprung–Russell diagram | Plots the temperature of stars against their luminosity or the color of stars against their absolute magnitude. |
Luminosity | an absolute measure of radiated electromagnetic power, the radiant power emitted by a light-emitting object. |
Brightness | An attribute of visual perception in which a source appears to be radiating or reflecting light. |
Absolute Magnitude | A measure of the luminosity of a celestial object, on an inverse logarithmic astronomical magnitude scale. |
Temperature (K) | Measured in Kelvin. Color of star depends on temperature. Increases from right to left. |
H-R Diagram | Plots each star on a graph and measures the star's magnitude against its brightness. |
Apparent Magnitude | Tells us how bright an object appears from earth. |
Spectral Class | Stars are classified by the elements they absorb. |