right ascension

(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

（天文学）赤道坐标，指定从春分点到穿过天空中物体的小时圆交点的角度，沿天体赤道向东测量

usually expressed in hours and minutes and seconds

通常用小时、分钟和秒来表示

used with declination to specify positions on the celestial sphere

与赤纬连用以指定天球上的位置

one hour of right ascension equals fif degrees

赤经一小时等于十五度

RA

celestial longitude