The solar system once consisted of the central star, Hippoastron, and the various bodies within its gravitational sphere of influence. Hippoastron was destroyed long ago, however, and replaced with a new (much smaller) magical luminous body orbiting the planet Equus.
The planet of Equus is very similar to Earth. It has one moon, similar in size and distance to the moon of Earth. Synchronization between the current orbits of the (artificial) sun and the moon result in exactly one solar eclipse in every 360 day year.
Other planets in the system include Cernunnos, a gas giant similar in size to Jupiter, with at least fifteen moons. It has been magically bound to continue orbiting Equus at about the same distance as it once orbited Hippoastron.
There is also a remnant asteroid belt, consisting of mainly nickel-iron asteroids. An Oort cloud demarcates the approximate (former) outer boundaries of the solar system, but with the loss of the original sun, many of these Oort objects have begun drifting away on their own courses into interstellar space.