[sneak]

Sol is the name of our star, so there is only one Solar system.

[codeulike]

solar system (noun)

earth science - the sun and the group of planets that move around it, or a similar system somewhere else in the universe

(Definition of the solar system from the Cambridge Academic Content Dictionary © Cambridge University Press)

https://dictionary.cambridge.org/dictionary/english/solar-sy...

[vmception]

This is a more of an etymology issue than what you think, if you need to look up the word etymology, I'm referring to the the history of the words and not suggesting any changing meaning