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cross section of an astronomical observatoryclick to hear

cross section of an astronomical observatory prime focus observing capsule light prime focus observation post Cassegrain focus telescope primary mirror hour angle gear flat mirror telescope base horseshoe mount polar axis secondary mirror laboratory coudé focus interior dome shell exterior dome shell

prime focus observing capsule click to hear

Area where astronomers once gathered to monitor the exposure time of photographic plates.

light click to hear

Emitted by the celestial body, light is sent back toward the Cassegrain focus by the primary and secondary mirrors.

prime focus click to hear

Focal point of the primary mirror where the light rays concentrate.

observation post click to hear

Area where most observations are carried out.

Cassegrain focus click to hear

Focal point where the image forms; located behind the primary mirror.

telescope click to hear

Optical instrument that uses an objective mirror to observe celestial bodies.

primary mirror click to hear

Mirror that reflects the light of celestial bodies, directing it toward the prime focus.

hour angle gear click to hear

Drive mechanism allowing the telescope to follow the polar axis.

flat mirror click to hear

Adjustable mirror making it possible to choose the location of the focus.

telescope base click to hear

Pedestal on which the telescope mount rests.

horseshoe mount click to hear

Mount used to support a large telescope and point it toward the celestial pole.

polar axis click to hear

Axis parallel to Earth’s axis of rotation; its rotation is opposite to that of Earth, making it possible to capture fixed images of an observed celestial body.

secondary mirror click to hear

Mirror that intercepts light and redirects it toward the Cassegrain focus through a hole in the center of the primary mirror.

laboratory click to hear

Area where the chemical composition of observed celestial bodies is studied using spectroscopy.

coudé focus click to hear

Focal point located at a distance from the telescope, obtained using a series of mirrors; stationary, it is used to conduct complex analyses and experiments.

interior dome shell click to hear

Regulates the temperature of the telescope so as to avoid air turbulence and prevent the mirror from becoming deformed.

exterior dome shell click to hear

Protects against foul weather.