An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

A constituent of a composite astronomical object which has a motion directed towards the observer, as revealed by its spectrum.

→ blueshift; → component.

A constituent part; an individual part of an organized whole.
One of two or more vectors having a sum equal to a given vector.

L. componentem, pr.p. of componere "to put together," → compose.

Hamneh from ham- "together," → com- + neh present tense stem of nehâdan "to put, place," → compose.

The rapid, systematic changes in the absorption parts of the → P Cygni profiles of the ultraviolet → resonance lines (Si IV, C IV, and N V) observed in a majority of massive → hot stars. DACs are typically seen to accelerate to the → blue wing of the profile over a few days, becoming narrower as they approach the → terminal velocity.

→ discrete; → absorption; → component.

Any device such as a → lens, → prism, → mirror, and/or other similar objects used in an → optical system.

→ optical; → component.

An electronic component which contains no source of power, in contrast to active components.

→ passive; → component.