Imprecisely at these apparent distances
Do you have a scientific citation for that, or is it your personal opinion?
Wow it's a very special bowl then giving this light show. These are not proofs they are observed patterns from which you draw conclusions.
This is basic physics. Line spectra...
Line spectra in stars. Normally all atoms seek the lowest energy state. But when they are heated or an input of energy is made, the electrons can be elevated to the next shell. Since they seek the lowest state, they radiate their energy in photons.
This is why your toaster glows, lightbulbs work and neon signs work.
Now, as the photons travel outward in the star, they encounter other atoms. Since electrons have specific energy levels in each element, they absorb specific photons based on wavelength. This is analogous to how if you shine a light on a solid, some will reflect but certain wavelengths will be absorbed. So when photons travel out in stars, they hit a blanket of cooler gas and some photons of certain wavelengths are absorbed. The spectrum of light the star emits therefore contain gaps in the electromagnetic spectrum.
We can compare the spectrum we receive, account for Doppler shifting, and identify which elements are present by which wavelengths of photons are missing. We know the absorption wavelengths of elements through controlled experiments.
This isn't guessing, its an understanding of physics and how the electromagnetic spectrum works.
Falsifiability is not a valid principle when the actual plausibility of a statement is impossible to test properly anyway as yet.
But we can test absorption spectra in labs. If I shine a broad spectrum of electromagnetic radiation through a cloud of gaseous iron into a spectrograph in a laboratory setting, we can see what wavelengths are absorbed by iron.
Then, if we see the same wavelengths are absent from the emission spectra of a star, we can conclude that there is iron in the outer layer of the given star.