Oh, here's the mod that adds the starry sky! https://mods.factorio.com/mod/Better_St ... rom=search

EDIT: Yeeahh, that's much better than vanilla:

I just stumbled on this topic whilst looking for a mod to do exactly what you're describing. Great stuff with the starry background! I love it. One nitpick that I might add is that although our actual sun does rotate around its own axis, but very, very slowly (it takes around 25 earth days to do one ...