Glossary of Telescopes

Basic Glossary Of Telescopes and Astronomy

Anytime you enter into a new area of study you invariably find yourself with a confusing amount of new terminology to master in order to communicate with or at least begin to understand the industry professionals.

This is unquestionably the case with astronomy both in terms that make reference to the cosmos and jargon that describe the various tools of the trade such as the telescope. There are a number of key words that relate to telescopes and astronomy in order for you to talk about them knowledgeably.

One of the first areas of specialization in telescopes concerns the different types of telescopes individuals make use of.

The three main designs of telescopes that the majority of astronomers use are the Refractor, the Reflector and Catadioptric telescope. These main groups are broken down into further sub-groups of which there are many.

Glossary of Telescopes

  • The refractor telescope uses a convex lens to focus the light on the eyepiece.
  • The reflector telescope has a concave lens which means it bends in. It uses mirrors to focus the image that you eventually see.
  • The Catadioptric uses both refracting lenses and reflecting mirrors in their design to provide a compact form factor..
  • A binocular telescope uses a set of telescopes mounted and synchronized so your view of the sky is 3-D.

Over and above the basic glossary of telescopes there are other terms that refer to parts of the telescope or to the science about how telescopes work

  • AltitudeThe Angular Distance between a celestial object and the closet point on th horizon.

  • Aperture refers to how large the lens of your telescope is. It is the key to how powerful your telescope is. Magnification has nothing to do with it, its all in the aperture.

  • Arc Minute A unit used to measure angles(there are 60 minutes of arc in 1 degree)

  • Astronomical Unit (AU)The average distance from the Earth to the Sun.(93 million miles)

  • Azimuth The angle between the position of a celestial object and true north,measured through east. North is at an azimuth of 0 degrees,east is at 90 degress, south at 180 degress and west 270 degrees.

  • Barlow Lens A lens that increases the focal length of a telescope, therby increasing the magnification of any eyepieces that are used with it.

  • CatadioptricA telescope that uses both lenes and mirrors to bring light into focus

  • Chromatic Aberration An aberration found in refreacting telescopes where not all colors of light can be brought to focus at the same time.

  • Collimation is a term for how well your telescope is set up to give a fine clear image. Your telescope needs to have good collimation so that you are not receiving a false image of the celestial body.

  • The Focuser is the housing that keeps the eyepiece of the telescope, or what you will look through, in place. .

  • Mount and Wedge. A telescope mount is a mechanical device that supports a telescope and is designed to support the mass of the telescope allowing for accurate pointing of the instrument. The mount and the wedge are there to assist you with a superior viewing session and to keep your expensive telescope safe from any mishaps.

  • An Altazimuth Mount refers to the tripod of the telescope that holds the device in place and makes it useful during a star gazing session. The altazimuth mouth allows the telescope to move both horizontally (which is the azimuth) and vertically. In this way you have full range to look at objects close to the horizon or directly overhead.

  • Equatorial Mount. A telescope mount in which one axes of movementis aligned with t he rotation axis of the Earth. To track the stars the telescope is moved in one axis onlay at a constant rate.

  • Eye Relief The maximum distance that an aobserver can place his eye from an eypiece and still see the full filed of view.

  • Coma has a different meaning compared to the one we are used to, and that’s not a bad thing. The coma is the fuzzy area on the outer rims of your view through the telescope. How large the coma is and to what degree it inhibits your observing may have is crucial to the performance of your telescope.

  • Planisphere. Is simply a star chart, a detailed map of where celestial objects are in the cosmos and allows you to easily locate the star you wish to study..

  • Star Diagonal. Is a right angled mirror or prism that diverts the beam of light from a telescope to the side, making it easier for an observer to position his head to look through the telescope

These are only a handful of the fundamental aspects of telescope operation. These have been intentionally chosen as the basic terms you need to know to debate telescopes intelligently. However your education and learning into the more intricate facets of astronomy and telescopes will go on for so long as you are an enthusiast of astronomy.

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