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physical object > artifact > device > instrument > telescope > electromagnetic telescope > reflector > Cassegrain

Cassegrain
subject			fact

Cassegrain	has secondary mirror shape convex hyperboloid
	has primary mirror shape concave paraboloid
	has optical design Cassegrain
	has definition An optical arrangement in which light rays striking the parabolic concave primary mirror of a reflecting telescope are reflected to the hyperbolic convex secondary mirror, and re-reflected through a hole bored in the primary to a focus behind it.
	has definition Refers to a design of reflecting telescopes in which the light collected and focussed by the large concave primary mirror is refocussed by a smaller convex secondary mirror on the same axis as the primary. The refocussed beam passes through a central hole cut into the primary mirror and emerges behind the primary.
	has definition Telescope devised by Cassegrain in which an auxiliary convex mirror reflects the magnified image, upside down, through a hole in the center of the main objective mirror - i.e., through the end of the telescope itself. It was, however, no improvement on the gregorian telescope invented probably slightly earlier.
	is a kind of reflector
reflector	has mirror maker the person, company or institution that created the mirror
	has mirror type material and other engineering details
	has mirror diameter equal to aperture (except for Schmidt which has aperture smaller than mirror diameter)
	has aperture or primary mirror diameter
telescope	has wavelength sensitivity
	has angular resolving power
	has effective diameter
	has focal ratio
	has operator
	has purpose observe celestial objects
	has location
artifact	has creator
	has creation date
	has owner
physical object	has angular momentum
	has mass
	has velocity
	has momentum
	has temperature
	has volume
	has extent
	has material

Kinds of Cassegrain :

• C. Donald Shane Telescope (15 facts) (120 inch)
• George Ellery Hale Telescope (17 facts) (200 inch)
• Hooker Telescope (16 facts) (100 inch)
• Large Binocular Telescope (15 facts) (LBT)
• NASA Infrared Telescope Facility (16 facts) (NASA IRTF)
• Nordic Optical Telescope (15 facts) (NOT)
• United Kingdom Infrared Telescope (17 facts) (UKIRT)

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