Richt ascension

Richt ascension (abbreviatit RA; seembol α) is the angular distance measured eastle alang the celestial equator frae the vernal equinox tae the oor circle o the pynt in quaisten.^[1] Whan combined wi declination, thir astronomical coordinates specify the direction o a pynt on the celestial sphere in the equatorial coordinate seestem.

Richt ascension an declination as seen on the ben-end o the celestial sphere. The primary direction o the seestem is the vernal equinox, the ascendin node o the ecliptic (reid) on the celestial equator (blae). Richt ascension is measured eastle alang the celestial equator frae the primary direction.

An auld term, richt ascension (Laitin, ascensio recta^[2]) refers tae the ascension, or the pynt on the celestial equator that rises wi ony celestial object, as seen frae the Yird's equator, whaur the celestial equator intersects the horizon at a richt angle. It is contrast wi oblique ascension, the pynt on the celestial equator that rises wi a celestial object as seen frae naur ony ither bit on Yird, whaur the celestial equator intersects the horizon at an oblique angle.^[3]