View source for Right ascension

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[[Category: Astronomy]]
== Explanation ==
Right ascension of an astronomical object like a [[star]] in the [[celestial sphere]] is analogous to the [[longitude]] on [[Earth]]. Right ascension is usually measured in [[hour]]s towards the east, which corresponds to 15° as 24 [[sidereal hour]]s marks a complete circle of 360°. Just like longitudes, the right ascensions run through the celestial poles, which are the extension of the poles of the earth. Together with [[declination]], they form the celestial coordinates.

== Frequently Asked Questions ==
=== What is the reference of the right ascension? ===
The reference point for longitude on earth is the prime meridian chosen to be at the Royal Observatory at Greenwich, Britain. For the celestial longitude or right ascension, this arbitrary reference point of 0h right ascension is chosen to be at the vernal [[equinox]] on March 21, by convention.