دورهی ِ هماگمی dowre-ye hamâgami
*Fr.: période synodique*
For planets, the mean interval of time between two successive
→ *conjunction*s
with or → *opposition*s
to the Sun. For example, → *Mars*
has a synodic period of 779.9 days from Earth;
thus Mars' oppositions occur once roughly 2.135 years. In comparison, the
synodic period of → *Venus*
is 583.9 days. If the sideral periods of the two bodies around the third are
denoted *T*_{1} and *T*_{2}, their synodic period
is given by: 1/*T*_{syn} =
|1/*T*_{1} - 1/*T*_{2}|. → *synodic*; → *period*. |