What Do You See; Introduction To Spectroscopy; In The Beginning - shelyak Lhires Lite Guide D'utilisateur

1.12 - What do you see ?

You mainly see two things:
First, you see all rainbow colors from red to blue with numerous
nuances – do not hesitate to ask the public to play with the scale index
and enumerate colors they see. This is a perfect exemple of the fact that
solar light, which appears white, is actually made of an infinite number of
colors. Note that those are pure colors made from a single wavelength –
you won't see pink or white for exemple which are combinations of
primary colors.
Second, you see thousands of absorption lines: those dark
horizontal lines are like ID signature of several chemical elements that
are on the Sun's photosphere. This illustrates how light from the Sun
(and other stars) carries rich information on the nature of the source...
Decoding this information is the job of astrophysists who, time after time,
understood how stars work. Welcome to the great world of Astrophysics!

1.13 - Introduction to Spectroscopy

1.13.1 In the beginning

Spectroscopy really started around 1666 when sir Isaac Newton
dispersed sunlight with a prism. But it's in 1802 that William Wollaston
discovered "dark" absorption lines, lines studied later by Joseph von
Fraunhofer who published a catalog of several hundred of those lines in
1815. We now have classified thousands of absorption lines in the solar
spectra.
In 1849, Léon Foucault studied emission lines produced by a
Sodium lap. Gustav Kirchoff and Robert Bunsen identified the same lines
in the solar spectra in 1857.
Lhires Lite – User Manual DC0005C 43 / 60