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They do it using spectral analysis. Different elements have different absorption bands of light. You can look at a graph of light from a star, with intensity of
by mjfl 12y ago
They do it using spectral analysis. Different elements have different absorption bands of light. You can look at a graph of light from a star, with intensity of light on the y-axis and frequency/wavelength (color) on the x-axis and that tells you quite a bit about the composition of the star.
- ars 12y agoThat only tells you the composition of the surface of the star. The heavier elements will be deeper. I suspect there is mathematical modeling. Interstellar dust might provide the spectrum instead of stars, although that really only tells us the composition of the milky way.
- mjfl 12y agoWell, in order to find the composition of interstellar dust, they will use spectral analysis as well...