Absolute Magnitude
The apparent magnitude that a star would possess it if were placed at a distance of 10 parsecs from ...
Absolute MagnitudeAccretion
An accumulation of dust and gas into larger bodies such as stars, planets and moons, or as discs aro...
AccretionAlbedo
The total ratio of sunlight reflected by a planet or body compared to what it receives from the S...
AlbedoAphelion
The point in the orbit of a planet or comet when it is furthest from the center of the Sun. (Opposi...
AphelionApogee
Similar to aphelion. The point in the orbit of the moon furthest from the center of the earth. (oppo...
ApogeeApoapsis
The point in an orbit when a planet is farthest from any body other than the Sun or the Earth. ...
ApoapsisArc Minute
A measure of angular separation. Arc is measured in a number of different units designed for various...
Arc MinuteAsteroid
(Also "planetoid") These are rocky bodies, the vast majority of which orbit the Sun between Mars and...
AsteroidAscending Node
The point in the orbit of an object, when it crosses the ecliptic, (or celestial equator) whilst mov...
Ascending NodeAstronomical Unit
A system of measurement used within our solar system based on the mean distance between the Earth an...
Astronomical UnitAurora
The Northern Lights. The brilliant displays of colored light in the sky at extreme northern and sout...
AuroraBinary Star
A double star; most commonly, a physical binary, or two stars which revolve about a common center of...
Binary StarBlue Moon
The second full moon in a calendar month, or the third full moon in a season containing four....
Blue MoonCelestial Equator
The projection of the Earth's equator upon the celestial sphere. Right ascension is the longitude me...
Celestial EquatorCelestial Sphere
The projection of space onto the night sky, an imaginary hollow sphere of infinite radius surroundin...
Celestial SphereCelestial Poles
The projection of the Earth's poles onto the celestial sphere. One of two points about which the Cel...
Celestial PolesChromosphere
The layer between the photosphere and the corona in the atmosphere of the Sun, or any other star, ma...
ChromosphereComa
(1) The luminous structure surrounding the head (solid portion) of a comet. (2) A defect in an opt...
ComaComet
An icy object in independent orbit about the Sun; smaller than a planet, usually having a highly ell...
CometConjunction
When two bodies appear to close together in the sky, i.e. they have the same Right Ascension. Mercur...
ConjunctionConstellation
An arbitrary grouping of stars which form a pattern. The 12 zodiacal constellations, Orion, the Big ...
ConstellationCorona
The outer layer, and hottest part, of the Sun's atmosphere; also the halo appearing around the black...
CoronaCoronagraph
A special telescope which blocks light from the Sun's disc, thus creating an artificial eclipse, in ...
CoronagraphCosmic Ray
An extremely fast, energetic and relativistic (high speed) charged particle. ...
Cosmic RayCosmos
The Universe: the word is derived from the Greek, meaning 'everything'. ...
CosmosAstronomical terms by letter:
A B C D E F G H I J K L M N O P Q R S T U V W X Y ZGotoHoroscope's mobile App for your Zodiac sign. Available on Google Play
Google Play and the Google Play logo are trademarks of Google LLC.