Tuesday, September 10, 2019
Astronomy 101 for 2 year college Lab Report Example | Topics and Well Written Essays - 500 words
Astronomy 101 for 2 year college - Lab Report Example 5% of them seem to split in two facular points; (h) they disappear simply by fading away in an intergranular space; (i) they never merge with another facular point or with a granule. C. Small dark regions called sunspots. Sunspots are cooler regions on the photosphere. Since they are 1000--1500 K cooler than the rest of the photosphere, they do not emit as much light and appear darker. B. During a total solar eclipse, an exceptional situation occurs, and for a few fleeting seconds, an emission spectrum can be observed. This happens at the very beginning of totality and just after the last bit of photosphere has been covered by the Moon. (Picture 1) For a period of several to perhaps ten seconds the chromosphere is visible as a red arc. (Recall that the chromosphere is a very thin layer just above the photosphere.) Often prominences are seen jutting from the chromosphere. The deep red color of the chromosphere comes from very strong emission in the hydrogen-alpha line at 656 nm. Because the chromosphere is quite rare and hot (with a temperature of about 10,000 K) it shows an emission spectrum in the absence of any light from the much brighter photosphere. Of course, the advance of the Moon soon covers the chromosphere and then the much rarer corona becomes visible as a broad white halo. Within minutes totality reaches completion, the chromosphere reappears on the o pposite side of the Sun followed seconds later by the overwhelming brightness of the photosphere. (Picture 2) Because the chromosphere is so thin, it forms an ideal subject for spectral imaging. A diffraction grating inserted in the light path of a telescope separates the light according to wavelength (just as in your spectrometer). An attached camera will then record the chromosphere imaged in each of the component wavelengths in its emission spectrum. This is the flash spectrum, so-called because of its brief accessibility. B. Because the chromosphere is quite rare and hot (with a temperature of
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