[1] Otherwise the stellar matter is restricted to atoms and ions in the forms of gas or – at very high temperatures – plasma.
Similar absorption bands can be found through observation of solar sun spots, which are cool enough to allow persistence of stellar molecules.
Molecules found in the Sun include MgH, CaH, FeH, CrH, NaH, OH, SiH, VO, and TiO.
Others include CN, CH, MgF, NH, C2, SrF, ZrO, YO, ScO, and BH.
[6] Measurements of simple molecules that may be found in stars are performed in laboratories to determine the wavelengths of the spectra lines.
Also, it is important to measure the dissociation energy and oscillator strengths (how strongly the molecule interacts with electromagnetic radiation).
[6] A numerical model of a star's atmosphere will calculate pressures and temperatures at different depths, and can predict the spectrum for different elemental concentrations.