A model of planets orbiting a star is called a planetary system.

Here's a breakdown of the terms:

* Planet: A celestial body that orbits a star and is massive enough for its own gravity to shape it into a nearly round object.

* Star: A giant ball of hot gas that produces light and heat through nuclear fusion.

* System: A group of things that work together as a whole.

So, a planetary system is a system consisting of a star and the planets that orbit it.