this galaxy is a complete shader on just a simple circle , it can be duplicated multiple times and there will be no lag at all because it is very low poly .when you go to rendered view please wait for like 5 to 7 seconds until the it is completely loaded .if you want you can turn off the compositor or change the compositor nodes until you get your desired look.it can be used for long to mid range in a scene .I am glad if you liked it and thank you for taking a look on my work.