Celestial Longitude (Noun)
Meaning
(astronomy) the equatorial coordinate specifying the angle, measured eastward along the celestial equator, from the vernal equinox to the intersection of the hour circle that passes through an object in the sky; usually expressed in hours and minutes and seconds; used with declination to specify positions on the celestial sphere; "one hour of right ascension equals fifteen degrees".
Classification
Nouns denoting spatial position.
Examples
- The celestial longitude of the star is 23 hours, 45 minutes, and 10 seconds.
- In the equatorial coordinate system, celestial longitude is used in conjunction with declination to specify positions on the celestial sphere.
- The vernal equinox is the reference point for measuring celestial longitude, which is the angular distance along the celestial equator to a celestial object.
- The right ascension of a star is equivalent to its celestial longitude, but is usually expressed in hours, minutes, and seconds.
- To calculate the position of a planet in the sky, astronomers use celestial longitude and declination to pinpoint its location on the celestial sphere.