Key Terms
- adaptive optics
- systems used with telescopes that can compensate for distortions in an image introduced by the atmosphere, thus resulting in sharper images
- aperture
- diameter of the primary lens or mirror of a telescope
- charge-coupled device (CCD)
- array of high-sensitivity electronic detectors of electromagnetic radiation, used at the focus of a telescope (or camera lens) to record an image or spectrum
- chromatic aberration
- distortion that causes an image to appear fuzzy when each wavelength coming into a transparent material focuses at a different spot
- detector
- device sensitive to electromagnetic radiation that makes a record of astronomical observations
- eyepiece
- magnifying lens used to view the image produced by the objective lens or primary mirror of a telescope
- focus
- (of telescope) point where the rays of light converged by a mirror or lens meet
- interference
- process in which waves mix together such that their crests and troughs can alternately reinforce and cancel one another
- interferometer
- instrument that combines electromagnetic radiation from one or more telescopes to obtain a resolution equivalent to what would be obtained with a single telescope with a diameter equal to the baseline separating the individual separate telescopes
- interferometer array
- combination of multiple radio dishes to, in effect, work like a large number of two-dish interferometers
- prime focus
- point in a telescope where the objective lens or primary mirror focuses the light
- radar
- technique of transmitting radio waves to an object and then detecting the radiation that the object reflects back to the transmitter; used to measure the distance to, and motion of, a target object or to form images of it
- reflecting telescope
- telescope in which the principal light collector is a concave mirror
- refracting telescope
- telescope in which the principal light collector is a lens or system of lenses
- resolution
- detail in an image; specifically, the smallest angular (or linear) features that can be distinguished
- seeing
- unsteadiness of Earth’s atmosphere, which blurs telescopic images; good seeing means the atmosphere is steady
- telescope
- instrument for collecting visible-light or other electromagnetic radiation
This book was adapted from the following: Fraknoi, A., Morrison, D., & Wolff, S. C. (2016). Key Terms. In Astronomy. OpenStax. https://openstax.org/books/astronomy/pages/6-key-terms under a Creative Commons Attribution License 4.0
Access the entire book for free at https://openstax.org/books/astronomy/pages/1-introduction
