series is also traced in the solar spectrum, but is too far in the ultra-violet to be studied effectively in the stars.
The series lines[261] of Al+ and Al++, although they might be expected in the
stars, apparently have not yet been traced in stellar spectra.
SILICON (14)
Four stages of the silicon atom are observed in stellar spectra. The line at 3905 is found in the coolest stars, has an observed maximum[262] at
, and disappears at about
