Astrophysics and Cosmology
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Browse the glossary using this index
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A
Absorption spectrumA spectrum containing dark lines where specific wavelengths have been absorbed by a cooler gas. | |
Accretion diskhot material orbiting and falling toward a compact object. | |
Adaptive opticstechnology that corrects astronomical images for distortions caused by Earth's atmosphere. | |
Aphelionthe point in an orbit farthest from the Sun. | |
Apparent BrightnessHow bright a star appears from Earth. | |
Artificial intelligencecomputer systems capable of tasks such as pattern recognition, classification, and prediction. | |
Artificial satellitea human-made object placed into orbit. | |
Astrometryprecise measurement of the positions and motions of stars. | |
Astronomical UnitThe average distance between the Earth and the Sun (about 150 million kilometres). | |
Astrophysicsthe application of physics to understanding astronomical objects and the Universe. | |