Technical description:
The Canada-France-Hawaii telescope structure is based on an equatorial mount design, with one of the axis of rotation set parallel to the axis of the Earth¹s rotation. The mirror cell (the white circular structure at the bottom of the telescope, seen just above the person giving the scale on this photograph) holds and protects the most precious element: the 3.6-meter diameter mirror.
    Light from distant objects enters the dome through the slit, bounces back from the mirror such that it will focus, and create a crisp image at the prime focus, MegaPrime -where the image is captured by MegaCam, CFHT's revolutionary new camera.
    By today's standards, the CFHT telescope is a heavy structure compared to the diameter of its mirror: the total mass of the telescope is 325 tons, with 250 tons for the mobile section alone. Yet the telescope can point to any location in the sky with an accuracy of 3 thousandths of a degree - and can follow astronomical objects with an even better accuracy, thanks to an automated guiding mechanism that compensates for the apparent motion of the sky due to the Earth's rotation. 
 

Credit line: "Canada-France-Hawaii Telescope / 2003"

Copyright © 2003 Canada-France-Hawaii Telescope Corporation