| the angular distance of a point on the celestial sphere from the great circle that is perpendicular to the ecliptic at the point of the vernal equinox, measured through 360° eastward parallel to the ecliptic. |
| celestial longitude n. The angular distance eastward from the vernal equinox along the ecliptic to the great circle drawn through the pole of the ecliptic and a celestial body. |
| celestial longitude
The position of a celestial object east of the vernal equinox along the ecliptic. Celestial longitude is measured in degrees eastward from the vernal equinox (0°) to the point where a great circle drawn through the object and the poles of the ecliptic intersects the ecliptic. Compare celestial latitude. See more at ecliptic coordinate system. |