恒星周期转会合周期转换器 — 公式

## Sidereal and Synodic Periods

A planet's **sidereal period** is its true orbital period. Its **synodic period** is how long between repeated alignments as viewed from Earth.

### Formula

**1/P_syn = |1/P_planet - 1/P_Earth|**

计算示例

Venus has a sidereal period of 224.7 days.

  1. 1/P_syn = |1/224.7 - 1/365.25|
  2. = |0.004451 - 0.002738| = 0.001713
  3. P_syn = 1/0.001713 ≈ 583.9 days