Young, Charles A. (Charles Augustus), 1834-1908, Young, Anne Sewell, b. 1871., ed · Boston, New York [etc.] Ginn and Company · leaf 160
Fig. 57. — Qiiiescent Prominences. its lines are conspicuous along with those of hydrogen. The D3 lineis not the only helium line, but the chromosphere spectrum containsat least three others that are always observable, besides several thatoccasionally make their appearance. The H and K lines of…
Astronomy · Constellations
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