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Astronomy

The Analysis of Stellar Spectra for Radial Velocity Measurements

Quick fact

By measuring tiny shifts in the wavelengths of absorption lines, astronomers can detect a star's motion along our line of sight with a precision of about 1 meter per second—roughly the speed of a brisk walk. This sensitivity has allowed the discovery of thousands of exoplanets.

Why this is interesting

You're looking at a star's rainbow, but its dark lines are actually a cosmic speedometer. How can a shift in those lines reveal whether a star is moving toward us or away?

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The Analysis of Stellar Spectra for Radial Velocity Measurements

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