Looks like a great start to me!
My only words of advice are: Don't get too attached.
The alpha version of US2 is undergoing so many changes right now that your star system could easily become invalidated in future releases.
I have a star system from the original US that I'd like to redesign in US2, but the properties panel in US2 is still a WIP and won't allow me to refine the details (radius, mass, density, temperature, etc.) to the required values.