An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

1) A → mounting for → telescopes that permits both → vertical and → horizontal → rotation.
2) A telescope having such a mounting.
See also: → altazimuth coordinate system, → altazimuth instrument, → altazimuth mounting.

Altazimuth, from alt(itude) + → azimuth.

Farâzâ-sugân, from farâzâ, → altitude, + sugân, → azimuth.

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.

A telescope that moves vertically along the → altitude circle of a celestial body and horizontally along its → azimuth circle.

→ altazimuth; → instrument.

A → telescope mounting which has its two axes of movement aligned with the → horizon and the → zenith.

→ mounting; → mounting.

Same as → altazimuth mounting.

→ altitude; → azimuth; → 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 (السمت) "the directions, ways," pl. of as-samt "the direction, way."

Sugân, from su "direction" + -gân direction suffix.

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.

→ azimuth; → circle.

Or, or pertaining to an → azimuth.

→ azimuth + → -al.

In → spherical coordinates, an angle measured from the x-axis in the xy-plane.

Azimuthal, adj. from azimuth; → angle.

In the → solar dynamo model, a magnetic field that points from east to west or vice-versa.

→ azimuthal; → magnetic; → field.

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.

In quantum mechanics, a quantum number that distinguishes the different shapes of the orbitals.

Azimuthal, adj. from → azimuth; → quantum number.

The difference in → azimuth between the → Moon and the → Sun.

→ relative; → azimuth.