Question

How is heliocentric longitude is used to show the position of planets in orbit around the Sun?

Answer 1

A planet's position about the Sun, at any instant, can be marked with the triad (distance from the Sun, latitude referred to the Earth/s ecliptic, longitude referred to the Earth's vernal equinox)

Explanation:

If the heliocentric distance of a planet at any instant is r, its

heliocentric N/S latitude referred to the Earth's ecliptic ( latitude 0 ) is `theta`

and its heliocentric longitude from the Earth's vernal equinox (about

March 21, longitude 0) ) is `beta`, the heliocentric location of the planet P is given

by `P (r, theta, beta)`.

In this brief explanatory note, I have not used the conventional Planetarium symbols.