Foundation Series:
1. Trantor
2. Helicon
3. Terminus
4. Vega
Hitchhiker's Guide to the Galaxy:
5. Golgafrincham
6. Magrathea
7. Krikkit
8. Milliways
I am not familiar with the Cthulhu mythos, but I picked some planets from https://en.wikipedia.org/wiki/Extraterrestrial_places_in_the_Cthulhu_Mythos
9. Abbith: It is inhabited by metallic brains, wise with the ultimate secrets of the universe
10. Celaeno
11. Glyu-Uho (or Betelgeuse)
12. Gnarr-Kthun (black hole)
13. Haddath
14. Kr’llyand: a green star and a dead one (likely a black hole or a brown dwarf)
15. Mthura: Dark planet inhabited by crystalline beings
16. Nyil-yath Rho: An ill-omened dark star with horrible past and future.
17. Tindalos: A place exited on Earth far in the past or a far-flung planet orbiting a black hole
18. Xoth: green binary star where Cthulhu and his ilk once lived before coming to earth
19. Yaddith
20. Yith The original homeworld of the Great Race of Yith
21. Yadoth
22. Yuggoth (yeah I know it's Pluto but in SCO maybe it could be somewhere else?)
