Spectra

The ligth is composed of different wavelength, or frequencies. Each frequency can be absorbed by different molecules, or atomic species. By looking at the light coming from exoplanets, we can therefore get an idea of what is inside the atmosphere: water, carbon monoxide, etc... With optical interferometry, we can precisely distinguish the light coming from the star from the light shined by the exoplanet. This is how we can get extraordinary spectrum, and information about the composition of exoplanets