In celestial mechanics, the true anomaly is an angular parameter that defines the position of a body moving along a Keplerian orbit. It is the angle between the direction of periapsis and the current position of the body, as seen from the main focus of the ellipse (the point around which the object orbits).
The true anomaly is usually denoted by the Greek letters or, or the Latin letter .
The true anomaly is one of three angular parameters ("anomalies") that define a position along an orbit; the other two being the eccentric anomaly and the mean anomaly.
Famous quotes containing the word true:
“It is a very true and expressive phrase, “He looked daggers at me,” for the first pattern and prototype of all daggers must have been a glance of the eye.... It is wonderful how we get about the streets without being wounded by these delicate and glancing weapons, a man can so nimbly whip out his rapier, or without being noticed carry it unsheathed. Yet it is rare that one gets seriously looked at.”
—Henry David Thoreau (1817–1862)