These definite characteristics allow elements to be identified by their atomic emission spectrum.
Finally, there are Be stars that show a prominent emission spectrum of hydrogen.
This is possible because each of the different fluorescent dyes can be associated with a specific emission spectra.
The rule is relevant in understanding the emission spectrum of an excited molecule.
Excimer formation also causes a red shift in the emission spectrum.
This leads to an altered emission spectrum, which is significantly narrowed.
A second, related, puzzle was the emission spectrum of atoms.
So the researchers "simply" had to compare emission spectra between the star and various elements on the periodic table.
The electronic properties (ionization and/or the emission spectrum) are necessary.
First, it cuts out longer wavelengths so you can use the tip design to choose your emission spectrum (to a certain extent).