| A | B |
|---|
| electromagnetic spectrum | the arangement of electromagnetic radiation according to wavelength |
| photon | a small packet of light energy |
| Doppler effect | the apparent change in frequency of electromagnetic or sound waves caused by the relative motions of the source and the observer |
| refracting telescope | a telescope that uses a lens to bend and concentrate the light from distant stars |
| reflecting telescope | a telescope that concentrates light from distant objects by using a concave mirror |
| radio telescope | a telescope designed to make observations in radio wavelenghts |
| corona | the outer weak layer of the solar atmosphere |
| prominence | the concentration of gases above the solar surface that appears as a bright archlike structure |
| solar flare | a sudden and tremendous eruption in the solar chromosphere |
| aurora | the bright display of everchanging light caused by solar radiation interacting with the upper atmosphere in the region of the poles |
| nuclear fusion | the way in which the sun produces energy; Nuclear fusion occurs when less massive nuclei combine into more massive nuclei, releasing tremendous amounts of energy |
| sunspot | a dark spot on the sun, which is cool by contrast to the surrounding photosphere |
