Kirchhoff's Laws
In early 1860's, Kirchhoff made three statements about Spectral Formation which
have since become known as Kirchhoff's Laws of Spectral Formation.
these statements concern when one should expect to see continuous
spectra, emission line spectra, and absorption line spectra.
For the following situations:
Kirchhoff's Three Laws:
- A hot opaque body, such as a hot, dense gas produces a continuous
spectrum
- A hot, transparent gas produces an emission line spectrum
- A cool, transparent (dilute) gas in front of a source of continuous emission
produces an absorption line spectrum.
Based on these rules, we may infer that the continuous emission from stars comes from
the dense, hot regions of the atmosphere while the absorption lines are formed
in the cooler overlying layers of the atmosphere. This picture is roughly
correct, however, in deatail, we know that this picture is oversimplified. In
reality, the situation is more complex in that the continuum and the spectral
lines are formed over larger regions and that the regions over which they are
formed are not distinct from one and another.
Based on Kirchhoff's Laws, describe how you would expect
the Solar spectrum to vary
during a Solar eclipse.