Search results
Results from the WOW.Com Content Network
A reflecting telescope (also called a reflector) is a telescope that uses a single or a combination of curved mirrors that reflect light and form an image. The reflecting telescope was invented in the 17th century by Isaac Newton as an alternative to the refracting telescope which, at that time, was a design that suffered from severe chromatic ...
Telecompressor or focal reducer: Optical element to decrease the telescope's focal length and magnification (usually by a fixed percentage) and widen the field of view, providing opposite effects of a Barlow lens. Star Diagonal: Used to change the angle of the light coming out of a telescope, for easier viewing.
The 100-inch (2.54 m) Hooker reflecting telescope at Mount Wilson Observatory near Los Angeles, USA, used by Edwin Hubble to measure galaxy redshifts and discover the general expansion of the universe. A telescope is a device used to observe distant objects by their emission, absorption, or reflection of electromagnetic radiation. [1]
The Houghton telescope or Lurie–Houghton telescope is a design that uses a wide compound positive-negative lens over the entire front aperture to correct spherical aberration of the main mirror. If desired, the two corrector elements can be made with the same type of glass, since the Houghton corrector's chromatic aberration is minimal.
Newtonian telescope design. A Newtonian telescope is composed of a primary mirror or objective, usually parabolic in shape, and a smaller flat secondary mirror.The primary mirror makes it possible to collect light from the pointed region of the sky, while the secondary mirror redirects the light out of the optical axis at a right angle so it can be viewed with an eyepiece.
Active optics is a technology used with reflecting telescopes developed in the 1980s, [1] which actively shapes a telescope's mirrors to prevent deformation due to external influences such as wind, temperature, and mechanical stress. Without active optics, the construction of 8 metre class telescopes is not possible, nor would telescopes with ...
A telescope with only one curved mirror, such as a Newtonian telescope, will always have aberrations. If the mirror is spherical, it will suffer primarily from spherical aberration . If the mirror is made parabolic, to correct the spherical aberration, then it still suffers from coma and astigmatism , since there are no additional design ...
The twin 10-meter telescopes at W. M. Keck Observatory in Hawaii, the 8.2-meter Subaru Telescope sited next to them, the four 8.2-meter Unit Telescopes of ESO's Very Large Telescope and their predecessor the 3.6-meter New Technology Telescope are notable examples that support an array of specialized instruments on their Nasmyth platforms, with a similar design being used for the future Thirty ...