This charging information does not apply to the current GEN IV stars as they charge very easy with a regular bedroom light or afternoon daylight but if you want to super charge even the current stars up to their peak read on. You should think of charging the stars the same as using a dimmer so if you do not charge them at all they will still work perfect but at a lower intensity level.
The globe pictured is a Phillips 24watt compact fluorescent and has a brightness output of 1450 lumens and a cool white light output you do not want to use warm white light. You want the lamp sitting in a central room position where the globe is around 5 feet below the ceiling to have a good light spread and in many cases a good position will be towards the end of the bed. Turn the lamp on for a few minutes to max charge the stars and they will be working perfect from that point on until the next morning or until light comes back into the room.Placing a high lumen globe in an existing light socket on a ceiling will not charge the stars in the same way as the light needs to come from a few feet below the ceiling but you still may get enough charging to suit.
Be sure to purchase your globe based on the lumen output and not the watt rating as wattage does not define lumen output and have a minimum 1400+ lumens. This globe type is very power efficient and costs hardly anything to run so experiment with different charging times and positions to find the level that works best for your star ceiling.
If you are not on a tight budget you could hard mount a lamp like in these images but you need to make sure that the lamp shade is very short so it does not restrict the full light output of the globe. As with the free lamp these light fittings should be around 5 feet below the ceiling level to ensure even charging of the stars. You can also use the 2 or 4 foot fluorescent shop lights in place of the lamps and they do work with a diffuser fitted. These tube type lights also work great with a T8 black light tube replacing the original.
Max charging will only work with the past GEN III and the current GEN IV stars as the older star versions do not have the capacity to absorb the light from high lumen charging. You may get some benefit charging the older stars in this way if your regular ceiling light is not very bright or you have flat spots or dull zones anywhere in your current star ceiling.