is a 7-star system possible?
In my mind, I think that it is POSSIBLE, yet so UNLIKELY, it might as well be impossible.
I would like 2 answers: 1. possibility according to physics and 2. statistical probability in the event that it is in fact physically possible.
Thank you 
Comments
Sure, it could be. However the orbital mechanics for a seven-star system can be very complex, and the system may not be stable, with one or more of the stars colliding or being ejected.
1. I think you are right that it would be possible. If you have one huge star and six smaller ones then the system would work kind of like a regular solar system. If the seven stars were of similar size then it would be very unlikely that they would ever establish a balanced system, I have not done any calculations, but if you had two binary pairs (where two stars orbit the center of mass instead of one star orbiting the other), and if those two binary pairs circled around the center of mass of the entire system, then maybe they could be close enough that the 7th start could orbit around the entire system. It would have to be traveling very fast, maybe too fast to be possible.
2. It has been too long since I took classes about such things so I better leave it to others to comment on the probability.