# Anomalies for Planetary Motion

Anomalies for Planetary Motion

The Kepler motion of a planet (brown dot) around a star (yellow dot) follows an ellipse. Given a semimajor axis and eccentricity , the current position of the planet at time since the perihelion passage is given by the true anomaly . To determine this, we first have to calculate the eccentric anomaly from the mean anomaly .

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