Detecting the Sun's Atmosphere
| The PHOTOSPHERE is best seen with normal visible light. This is because it acts like a very hot (5800 K) black body radiator, which has its PEAK in the optical. On its surface, you can see granules and sunspots see movie. | The CHROMOSPHERE is tenuous and not so hot. However, it can be seen in emission lines, such as the main RED line of Hydrogen, called H-Alpha. Images made in this way are called filtergrams. In the chromosphere one sees jets of gas moving out from the sun, called spicules |
The CORONA is extremely tenuous. However, it is also extremely hot. The Corona is so hot, it excites atoms to emit light at X-Ray wavelengths. Thus the Corona is best seen when looking at X-Ray light.
| The Corona can be seen with visible light during an eclipse, when the Sun's bright photosphere is blocked out by the Moon. (See a movie of an eclipse HERE(mpeg). X-ray movies and images here. |
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