1) A → mounting for → telescopes
that permits both → vertical and
→ horizontal → rotation.
Altazimuth, from alt(itude) + → azimuth.
altazimuth coordinate system
râžmân-e hamârâhâ-ye farâzâ-sugân
Fr.: coordonnées azimutales
The coordinate system in which the position of a body on the → celestial sphere is described with respect to an observer's → celestial horizon and → zenith. The coordinates of a point in this system are its → altitude on the → vertical circle, and its → azimuth westward (clockwise) along the celestial horizon from the observer's south. Same as → horizon coordinate system.
→ altazimuth; → coordinate; → system.
Fr.: instrument altazimutal
A telescope that moves vertically along the → altitude circle of a celestial body and horizontally along its → azimuth circle.
→ altazimuth; → instrument.
Fr.: monture altazimutale
A → telescope mounting which has its two axes of movement aligned with the → horizon and the → zenith.
Fr.: monture altitude-azimutale
Same as → altazimuth mounting.
The → angular distance from the → North point eastward to the intersection of the → horizon with the → vertical circle passing through the object. Azimuth is 0° for an object due north, 90° due east, 180° due south, and 270° due west. → Altitude and azimuth constitute the → horizon coordinate system.
From O.Fr. azimut, from Ar. as-sumut (
Sugân, from su "direction" + -gân direction suffix.
parhun-e sugân, dâyere-ye ~
Fr.: cercle d'azimut
One of great circles of the → celestial sphere which passes through the → zenith, → nadir, and the star, cutting the horizon at right angles. Same as → vertical circle.
Or, or pertaining to an → azimuth.
Fr.: angle azimutal
In → spherical coordinates, an angle measured from the x-axis in the xy-plane.
Azimuthal, adj. from azimuth; → angle.
azimuthal magnetic field
meydân-e meqnâtisi-ye sugâni
Fr.: champ magnétiquue azimutal
In the → solar dynamo model, a magnetic field that points from east to west or vice-versa.
Fr.: projection azimutale
A map projection on which the → azimuths of all points are shown correctly with respect to the center. A plane tangent to one of the Earth's poles is the basis for polar azimuthal projection.
→ azimuthal; → projection.
azimuthal quantum number
adad-e kuântomi-ye sugâni
Fr.: nombre quantique azimutal
In quantum mechanics, a quantum number that distinguishes the different shapes of the orbitals.
Azimuthal, adj. from → azimuth; → quantum number.
Fr.: azimut relatif
The difference in → azimuth between the → Moon and the → Sun.