right ascensionn.Abbr. R.A.Astronomy（名词）缩写 R.A.【天文学】
The angular distance of a celestial body or point on the celestial sphere, measured eastward from the vernal equinox along the celestial equator to the hour circle of the body or point and expressed in degrees or hours.赤经：在天球上某天体或点的角距离。从春分点沿天赤道向东测量，直到该天体或该点的时圈并由角度和小时来表示