太陽光譜。太陽是一個近似黑體幅射源，因此應該會放出所有顏色的光。圖中黑色的位置是由於太陽表面及周圍的氣體吸收所致。
APOD: All the Colors of the Sun (2015 Jun 28)
Credit & Copyright: Nigel Sharp (NSF),
FTS, NSO, KPNO, AURA, NSF
http://apod.nasa.gov/apod/ap150628.html
Explanation: It is still not known why the Sun's light is missing some colors. Here are all the visible colors of the Sun, produced by passing the Sun's light through a prism-like device. The spectrum was created at the McMath-Pierce Solar Observatory and shows, first off, that although our white-appearing Sun emits light of nearly every color, it does indeed appear brightest in yellow-green light. The dark patches in the above spectrum arise from gas at or above the Sun's surface absorbing sunlight emitted below. Since different types of gas absorb different colors of light, it is possible to determine what gasses compose the Sun. Helium, for example, was first discovered in 1870 on a solar spectrum and only later found here on Earth. Today, the majority of spectral absorption lines have been identified - but not all.
http://www.noao.edu/scope/copyright.html
http://www.noao.edu/noao/scistaff/sharp.html
http://www.noao.edu/noao/staff/plymate/fts/aboutFTS.html
http://www.nso.edu/
http://www.noao.edu/kpno/
http://www.aura-astronomy.org/
http://www.nsf.gov/
Starship Asterisk* • APOD Discussion Page
http://asterisk.apod.com/discuss_apod.php?date=150628
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