According to Education.nationalgeographic, "A star system is a group of planets, meteors, or other objects that orbit a large star. While there are many star systems, including at least 200 billion other stars in our galaxy, there is only one solar system. That's because our sun is known by its Latin name, Sol.
So, ignoring our star system, when astronomers discovered other star systems, on what basis did they (or do they) define the boundary of a star system?
For example, when I was trying to understand what defines the boundary of a galaxy, I came across an article in Advanced Science News from last year. In that article, a team of people came up with their own explanation/definition for what defines the edge of a galaxy. They argue that the edge of a galaxy is defined as the point at which star formations inside the galaxy significantly drops.
So, in that same vein, what defines the edge/boundary of a star system?