coudé

Coudé is a French term derived from the verb "coudoyer," meaning to elbow or jostle. In various contexts, it signifies a close proximity or a side-by-side arrangement.

In astronomy, a coudé telescope employs a coudé focus. This setup utilizes a series of mirrors to redirect the light path from the telescope's primary mirror to a stationary observing point, typically located in a basement below the telescope. This configuration is advantageous as it allows for the mounting of heavy spectrographs and other instruments without requiring the telescope itself to rotate, thus simplifying observations and reducing mechanical strain. The coudé design was particularly popular in the mid-20th century for large reflecting telescopes.

Beyond astronomy, the term coudé can also be found in other fields. For instance, in some historical military formations, troops might advance "en coudé," implying a staggered or echelon formation. In a more general sense, "coudé" can describe anything that is placed or positioned alongside something else, often in a functional or supportive manner. The underlying concept remains that of adjacency or close interaction.