@Nine some fairly low power LEDs might do the job nicely, or maybe fibre optics if you put a false ceiling in
or there's the really fucking expensive option of GTLSs (gaseous tritium light sources) which would be awesome
@troubleMoney I got some cute battery powered LED fairy lights strung up (kinda badly) above my bed on a roofing beam and they're kinda nice b ut I always wanted glow in the dark stick on stars on my ceiling and never had them.
@Nine ah yeah, those ones, they're cool
you might be able to fit some LED strip lights so they shine on the stars and then turn those on for 10 minutes before bed to charge the stars