Aberration of light

Aberration of light

The Aberration of light It is the phenomenon by which the position of the stars appears displaced with respect to the real one.

This movement is the result of movements such as the rotation of the Earth, its orbital revolution around the Sun and the movement of the Solar System through space. Although the resulting speed of the observer is small (only 0.2% of the speed of light), it is sufficient to produce an apparent displacement of the light rays that come from a celestial object.

Intuitively, it can be explained by observing how the occupants of a car that moves under a perfectly vertical rain to the ground, have the feeling that it falls inclined towards the vehicle in which they travel. Similarly, the light rays of a star observed from Earth appear deviated and the source, therefore, displaced. This displacement reaches a maximum of 20.47 arc seconds, called the aberration constant.

The discovery of the aberration of light was published in 1729 by British astronomer James Bradley. and constituted the first observation test of the movement of the Earth around the Sun.

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Astronomy Glossary: ​​AOptical aberration