True longitude
Jump to navigation
Jump to search
In celestial mechanics, true longitude is the ecliptic longitude at which an orbiting body could actually be found if its inclination were zero. Together with the inclination and the ascending node, the true longitude can tell us the precise direction from the central object at which the body would be located at a particular time.
Calculation
The true longitude Template:Math can be calculated as follows:<ref name=Moulton_1970>Template:Cite book</ref><ref name=Roy_1978>Template:Cite book</ref><ref name=Brouwer_Clemence_1961>Template:Cite book</ref>
where:
- Template:Math is the orbit's true anomaly,
- Template:Math is the longitude of orbit's periapsis,
- Template:Math is the argument of periapsis, and
- Template:Math is the longitude of the orbit's ascending node,