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  3. Doppler Effect
Astrophysics

Doppler Effect

Definition

The change in frequency or wavelength of a wave relative to an observer moving relative to the source. In astronomy, it determines whether objects are moving toward or away from Earth by measuring spectral line shifts.

Related Terms

Redshift

An increase in wavelength of radiation from an object moving away from the observer. The redshift of distant galaxies pr...

Blueshift

A decrease in wavelength and increase in frequency of electromagnetic radiation from an object moving toward the observe...

Spectroscopy

The study of the interaction between matter and electromagnetic radiation. In astronomy, it reveals composition, tempera...

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Full Glossary

Browse all 66+ space and astronomy terms.

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