Location in Space

    Parallax = 0.28593˚± 0.00088 arc-seconds, which leads to;

        11.407 lightyears ± 0.035 lightyear

        721,383 AU ± 2,220 AU

Imagine standing on the north side of Earth's equatorial plane with the north celestial pole directly overhead and look toward the First Point of Aries (the point where the Ecliptic crosses the celestial equator, which now lies in Pisces, slightly southwest of the Circlet). Slide your gaze eastward (to your left) about one-eighth of a degree less than 115 degrees along the celestial equator, reaching a point south of where the Ecliptic passes through Gemini. Then tilt your view north a little less that 5-1/4 degrees. Procyon is the brightest star in your view at that point.

    Ecliptic Latitude; -15.9703762 degrees (-15˚ 58' 13.354") - 130.847t arcsec.

    Ecliptic Longitude; 115.7764721 degrees (115˚ 46' 35.300") - 50.900t arcsec.

        Total Proper Motion = 1.247 arcsec per year in a direction 214.5˚ counterclockwise from due celestial north.

    We refer the following to the plane of the sky, which we define as the plane comprising all straight lines that cross our line of sight through the barycenter of the Procyon system and that pass through that barycenter. One of those lines coincides with the system's line of nodes, the line where the system's orbital plane crosses the plane of the sky. As a matter of definition, astronomers refer to the node where the system's secondary (the white dwarf Procyon B in this case) crosses the plane of the sky moving at least partly away from Earth as the ascending node.

    Inclination; the angle between the plane of the stars' orbits and the plane of the sky. Because their orbit has an inclination less than 90 degrees, the stars of Procyon appear to us to revolve counterclockwise about their barycenter.

i=31.1± 0.6 degrees.

    Position angle of the secondary's ascending node; the angle between the Ecliptic north vector (projected onto the sky) and the line of nodes, measured counterclockwise toward the system's ascending node.

    Longitude of Periastron (or Argument of Periastron); the angle between the line of nodes and the orbit's major axis (line of apsides), measured in the prograde direction (the direction of the secondary's motion) in the plane of the true orbit, from the secondary's ascending node to the secondary's periastron

    On a piece of stiff paper draw an ellipse of eccentricity e=0.407 and draw an arrow indicating the direction of the star's motion on the orbit that the ellipse represents. Look toward Procyon and so hold the paper that the line of apsides coincides with your line of sight and the north vector of the orbit (defined by the right-hand rule: when your right thumb, extended in a thumbs-up gesture, points north, the fingers of that hand curl in the same way that the body moves on its orbit) points Ecliptic north. Turn the paper counterclockwise 7.3 degrees, then so turn it that the orbit turns in the retrograde direction by 177.8 degrees, and finally turn it 58.9 degrees about the line of nodes in accordance with the left-hand rule (with your left thumb pointing from the ascending node to the descending node, your fingers curl in the direction you must turn the paper).

    Orbital Period: 40.82± 0.06 years.

            2. 1967.97± 0.05 (AD 1967 Dec 20)

        Age; 1.7" 0.3 billion years