How the 1868 Solar Eclipse Revealed a Mysterious Yellow Spectral Line
Quick Look
The 1868 solar eclipse led astronomers, including Pierre Janssen, to discover a mysterious yellow spectral line in the Sun's prominences, later linked to helium, though Janssen did not identify the element himself.
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Why It Matters
The 1868 solar eclipse provided a unique opportunity for astronomers to study the Sun's prominences using spectroscopy.
The article discusses the 1868 solar eclipse's role in revealing a mysterious yellow spectral line in the Sun's prominences, later identified as helium. Pierre Janssen observed this line but did not discover helium. Norman Lockyer named the element helium after further investigation. William Ramsay finally isolated helium on Earth in 1895. Janssen's contribution was primarily the development of the prominence method for studying the Sun's atmosphere.
Open Questions
- What were the exact conditions under which Lockyer and Frankland attempted to reproduce the D3 line in the lab?