parallactic ellipse

American  

noun

Astronomy.

1. the apparent ellipse, as seen against the background of more distant stars, described annually by a nearby star because of the earth's orbital motion around the sun.

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Example Sentences

At a certain date, which can be readily computed, the star is at one end of the parallactic ellipse, and six months later the star is at the other end.

From The Story of the Heavens by Ball, Robert S. (Robert Stawell), Sir

In the course of a year it is found that the difference in declination undergoes a periodic change, and from that change the parallactic ellipse can be computed.

From The Story of the Heavens by Ball, Robert S. (Robert Stawell), Sir

In a somewhat more popular manner, we would say that one thousand times the major axis of the very largest parallactic ellipse would not be as great as the diameter of the full moon.

From The Story of the Heavens by Ball, Robert S. (Robert Stawell), Sir

If a penny-piece were placed on this sphere, in front of each of the stars, every parallactic ellipse would be totally concealed.

From The Story of the Heavens by Ball, Robert S. (Robert Stawell), Sir