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Ch 10 '14
Astronomy
Term | Definition |
---|---|
astronomers | People who study outer space and celestial bodies. |
Big Bang theory | A theory to explain how the universe happened. |
celestial bodies | Everything that is matter in the universe. |
cosmological red shift | Spectral lines are all shifted to longer (redder) wavelengths. |
electromagnetic radiation | Energy that comes out in the form of waves. Electromagnetic, meaning from the electromagnetic spectrum. |
elliptical galaxy | A type of galaxy having an approximately ellipsoidal shape and a smooth, nearly featureless brightness profile. |
irregular galaxy | A galaxy that does not have a distinct regular shape, unlike a spiral or an elliptical galaxy. . |
nebula | The place where stars are made from dust and hydrogen. |
red shift | The displacement of spectral lines toward longer wavelengths (the red end of the spectrum) in radiation from distant galaxies and celestial objects. |
spectroscope | An apparatus for producing and recording spectra for examination. |
spiral galaxy | A galaxy in which the stars and gas clouds are concentrated mainly in one or more spiral arms. |
star cluster | A group (hence cluster) of stars. |