Of a celestial object as seen from a particular location, the difference between the local sidereal time and the right ascension (H.A. = L.S.T. - R.A.).
the angle of a star's location away from the point on the celestial equator due south of an observer in the northern hemisphere. Postive is to the east of that point, negative to the west. It is measured in hours where 1 hour = 15°.
angular distance on the celestial sphere measured westward along the celestial equator from the meridian to the hour circle that passes through a celestial object.
Local Apparent Time expressed as the angular position of the Sun in its daily track. Measured from noon, it increases by 15º per hour with increasing time (i.e., morning hours are negative). Beware, this convention is not universal.
the angular distance along the celestial equator from the observer's meridian to the hour circle of a given celestial body
The angle, measured westwards around the celestial equator, between the observer's meridian and the hour circle of an object.
(HA). Angle between any two hour circles or between a meridian of longitude and an hour circle in the celestial sphere, generally measured westerly through 360 degrees, as in LHA. If hour angle is measured east or west through 180 degrees, it is identical with meridian angle, "t".
Hour angle is the difference between the Right Ascension of a planet and the Right Ascension circle on the Meridian at the time of observation. The Hour Angle is measured to the West from the Meridian.
The angular distance of a celestial object measured westward along the celestial equator from the zenith crossing.
Angle between antenna beam and meridian plane (measured in equatorial plane). Steering direction of a polar mount antenna.
The angle that the hour circle of a heavenly body makes with the observer's meridian at the celestial pole. It is measured positively westwards from the meridian from 0 to 24 hr, and it denoted in hours, minutes and seconds.
The time that has elapsed since an object was on the meridian or the time that will be needed to wait for an object to reach the meridian. West of the meridian - hour angle is positive, east it is negative.