* Our understanding of star systems: We usually think of star systems as a small group of stars gravitationally bound together (like our own Solar System with the Sun and its planets).
* Galaxies: The scale you're describing is closer to a galaxy. Galaxies are vast collections of stars, gas, dust, and dark matter held together by gravity. Our Milky Way galaxy contains hundreds of billions of stars.
* Galaxy clusters: There are even larger structures called galaxy clusters, containing hundreds or thousands of galaxies.
In summary: While there isn't a specific term for a "star system" with that many stars, it would be more accurately described as a galaxy or even a galaxy cluster.
