1. Galileo’s drawing of the Pleiades from the Sidereal Messenger (left) and an image from a modern replica of Galileo’s telescope (below).
Only the outlined stars in Galileo’s drawing are visible with the naked eye.

2. The Planck function for temperatures from 3500 - 5500 K (graphic stolen from wikipedia)

3. Solar spectrum, shown as through a prism (top) and in a plot of intensity vs. wavelength (side) (images taken from wikipedia)

4. Spectra for O - G stars (left) and G - M stars (right)

6. Element abundances in the Solar system (data from Lodders 2003)