Editing Equatorial coordinate system (section)

===Right ascension===
[[File:Hour angle still1.png|thumb|right|300px|As seen from above the [[Earth]]'s [[geographic pole|north pole]], a star's {{colorbox|cyan}}{{nbsp}}[[hour angle|local hour angle]] (LHA) for an {{colorbox|red}}{{nbsp}}observer near New York. Also depicted are the star's {{colorbox|green}}{{nbsp}}[[right ascension]] and {{colorbox|blue}}{{nbsp}}Greenwich hour angle (GHA), the {{colorbox|magenta}}{{nbsp}}[[sidereal time|local mean sidereal time]] (LMST) and {{colorbox|purple}}{{nbsp}}[[sidereal time|Greenwich mean sidereal time]] (GMST). The symbol ♈︎ identifies the [[equinox|March equinox]] direction.]]

{{Main|Right ascension}}
The right ascension symbol {{math|''α''}}, (lower case "alpha", abbreviated RA) measures the angular distance of an object eastward along the [[celestial equator]] from the March [[equinox]] to the [[hour circle]] passing through the object. The March equinox point is one of the two points where the [[ecliptic]] intersects the celestial equator. Right ascension is usually measured in [[sidereal time|sidereal]] hours, minutes and seconds instead of degrees, a result of the method of measuring right ascensions by [[Meridian circle|timing the passage of objects across the meridian]] as the [[Earth's rotation|Earth rotates]]. There are {{sfrac|360°|24<sup>h</sup>}} = 15° in one hour of right ascension, and 24<sup>h</sup> of right ascension around the entire [[celestial equator]].<ref name="calculator28"/><ref>
{{cite book
 | url=https://books.google.com/books?id=PJoUAQAAMAAJ
 | title = An Introduction to Astronomy
 | last1 = Moulton
 | first1 = Forest Ray
 | page=127
 | date = 1918
}}</ref><ref>
''Astronomical Almanac 2010'', p. M14
</ref>

When used together, right ascension and declination are usually abbreviated RA/Dec.