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right ascension Definition

right ascension

noun

Astron. the angular distance of the hour circle of a celestial body from the vernal equinox, measured eastward along the celestial equator and expressed in degrees (from 0 to 360) or, more commonly, in hours (from 0 to 24), minutes, and seconds: it is used with declination (sense ) to find an exact position in the sky: abbrev. RA

right ascension Usage Examples

Preposition: of

  • source: Ra The right ascension of the radio source in the selected equinox.
  • star: Ra The right ascension of the star in the selected equinox, i.e. , the optical position.
  • object: Ra The right ascension of the object in the selected equinox.
  • position: RA The right ascension of the position of maximum probability density for the X-ray source location in the selected equinox.
  • center: RA The right ascension of the center of best fit A2 error box.

Converse of object

increase: Sort by Sort output list by distance from search center ( in arcminutes ), increasing right ascension or declination, or stellar magnitude.

Preposition: in

  • equinox: RA The right ascension in the default equinox ( given to the nearest tenth of a second of time in the original catalog ).
  • radian: HOUR The size of one hour of right ascension in radians.