Spectroscopy Is How We See Stars
What is Spectroscopy?
Spectroscopy is the study of electromagnetic radiation and how it is affected upon the interaction of matter.
Spectroscopy Helps Astronomers
Astronomers can split light from space and examine its spectral lines to infer what compounds are emitted or absorbed.
Absorption Spectrum
The spectrum shown here is called an absorption spectrum. An absorption spectrum is only shown when you are looking directly at the light being produced from a star. This occurs when an incandescent light passes through a cool gas and the atoms in the gas absorb some lines in the spectrum. This creates the dark lines and the name, absorption spectrum.
Wavelength
The colors of visible light relates to wavelength. Light travels in waves, and the wavelength determines the color of light that can be observed.
How Do We Know What Stars Are Made Of?
We learn about them from the light they emit and astronomers pass starlight through the telescopes and into spectroscopes. The color that the starlight emits give clues to what is in the stars.
Stars Are Mostly Made of Hydrogen
How Do We Identify The Elements in a Star?
1. Invert the emission spectrum of the element you are looking for.
2. Make sure that it matches up with the star's spectral lines (so both look like an absorption spectrum). If the spectral lines match up, then that element is part of the star. If not, then try again because it is not part of the star.
3. Repeat until all elements have been located.