astronomy
About this set
Created by:
meredith245 on November 30, 2010
Subjects:
Log in to favorite or report as inappropriate.
Order by
54 terms
Terms | Definitions |
|---|---|
 1905 | current understanding of nature of light emerged |
| einstein | showed that light sometimes behaves as particles and sometimes as waves |
| wave model | wavelengths of radiation vary |
| white light | consists of several wavelengths corresponding to the colors of the rainbow |
| particle model | exert a pressure called radiation pressure on matter |
| photons | particles |
| particle model | shorter wavelengths correspond to more energetic photons |
| light comes from | movement of electrons in atoms |
| nucleus | contains protons and neutrons |
| element | atoms with the same number of protons |
| isotopes | atoms with varying numbers of neutrons |
| ions | atoms with varying numbers of electrons |
| spectral lines | when electron jumps form one energy level to another |
| 186,000 m/s | speed of light |
| visible light | only one small part of an array of energy |
| electromagnetic radiation | gamma rays, x-rays, UV light, visible light, infrared light, radio waves |
| visible light | only one type of electromagnetic radiation emitted by stars |
| each type of EM radiation | travels at exactly the same speed (speed of light) |
| peak color (wavelength) | shifts to shorter wavelengths as an object is heated |
| wavelength | inversely proportional to temperature |
| sun | emits all colors |
| sun | most intensely emits blue-green part of spectrum |
| temperature | learned by analyzing starlight |
| chemical composition | learn by analyzing starlight |
| spectroscopy | study of properties of light that depend on wavelength |
| spectrum | light pattern produced by passing light through a prism which spreads out the various wavelengths |
| continuous spectrum | produced by an incandescent solid, liquid, or high pressure gas |
| continuous spectrum | uninterrupted band of color |
| dark-line (absorption) spectrum | produced when light is passed through a comparatively cool, low pressure gas |
| dark-line (absorption) spectrum | appears as a continuous spectrum but with dark lines running through it |
| bright-light (emission) spectrum | produced by a hot (incandescent) gas under low pressure |
| bright-light (emission) spectrum | appears as a series of bright lines of particular wavelengths depending on the gas that produced them |
| dark-line (absorption) spectrum | most stars have |
| spectroscope | instrument used to spread out the light |
| emission and absorption spectra | allow astronomers to determine the elements present in a distant star |
| each chemical element | produces its own unique set of spectral lines when it burns |
| brightness of spectral lines | depend on conditions in spectrum's source |
| continuous spectrum | produced by a hot,dense gas or object - is a complete rainbow of colors without any specific spectral lines |
| emission line spectrum | produced by hot, rarefied gas - series of bright spectral lines against a dark background |
| absorption line spectrum | produced by a cool gas in front of a continuous light - series of dark spectral lines among the colors of the rainbow |
| movement | learned by analyzing starlight |
| doppler shift | allows astronomers to measure radial velocity |
| spectral lines | shift due to relative motion between the source and the observer |
| doppler effect | apparent change in wavelength of radiation caused by the relative motions of the source and observer |
| doppler effect | used to determine increasing distance (wavelength stretches) |
| doppler effect | used to determine decreasing distance (wavelength compresses) |
| velocity | larger doppler shifts indicate higher velocities |
| red shift | distance between the observer and the sources is increasing |
| blue shift | distance between the observer and the source is decreasing |
| radial velocity | learned by analyzing starlight |
| different types of EM radiation | require different types of telescopes |
| refracting telescope | uses a lens to concentrate incoming light |
| reflecting telescope | uses mirrors to concentrate incoming starlight |
| not all EM radiation | can penetrate earth's atmosphere |
First Time Here?
Welcome to Quizlet, a fun, free place to study. Try these flashcards, find others to study, or make your own.