Precisely measured fundamental quantities; such as, solar parallax, the constant of aberration, and the obliquity of the ecliptic.
A date designated by year, month, day, and decimal fraction of a day.
The distance of a celestial object from earth, given in any standard unit of astronomical measurement.
Any item used for the study of the positions, compositions, and movement of celestial bodies.
A building constructed to house astronomical instruments which allows people to observe objects in space.
An organization that conducts astronomical research through the use of such a structure.
astronomical photography (s) (noun)
, astronomical photographies (pl)
The use of photographs to record extraterrestrial objects in order to study their surface features, positions, motions, radiation, ans spectra.
The bending of light or a ray of celestial radiation as it passes into the atmosphere from space.
The twinkling of starlight caused by variations of refractivity in high-altitude layers of the earth's atmosphere.
astronomical spectrograph (s) (noun)
, astronomical spectrographs (pl)
A spectroscope in which the spectra of stars and other celestial objects are recorded on photographic film.
A spectroscope is an instrument for dispersing light; usually, light in the visible range, into a spectrum in order to measure it; such as, a continuous distribution of colored light produced when a beam of white light is dispersed into its components; for example, by a prism.
The analysis of radiant energy emitted by celestial objects in order to gather data about physical and chemical properties of celestial objects; such as, density, temperature, and chemical composition.
1. A telescope used for observing extraterrestrial objects.
2. A telescope that collects, detects, or records electromagnetic radiation emitted from extraterrestrial sources.
astronomical tidal constituent (noun)
, harmonic constituent, tidal constituent, constituent number (s)
; harmonic constituents, tidal constituents, constituent numbers (pl)
One of the harmonic elements in mathematical expressions and formulas for the forces and strong currents of the oceans: As an oceanographer, it was Hickory's responsibility to calculate the astronomical tidal constituent in the local harbor.
astronomical tide, astronomic tide
A tide caused by the attractive forces of the sun and moon, as opposed to a meteorological tide caused chiefly by the wind and atmospheric pressures.
1. The solar time in an astronomical day.
2. Any standard of time based on astronomical observations.
3. A system of time measurement formerly used by astronomers, based on solar time in a mean solar day beginning at noon, and superseded by civil time.
A line running across an area defined in surveying, located by observations of celestial bodies and subsequent computations.
Other "star" units:
You may also see an extensive list of astronomy; astronomical terms at this Get Words site.