Yeah... We see Hydaelyn (who is clearly the planet) being referred to as a "star" by individuals who call the planet they came from a "star" too. And life on Hydaelyn seems to come from Hydaelyn herself. Although... the dragons know that the sun is a ball of plasma in space, so there is that. They also are very sure that the sun is not alive.

The best way to think of it (I've found) is that Hydaelyn, the Source and the Shards all share the same 4D space. They all have the same sky, the same passage of time, etc. What they aren't is on the same "phase" or "wavelength" of reality or each other. The Source seems to be in the same "phase" as the rest of reality is, probably because it is the thing the rest of the Shards are copies of. The Source is where beings who are not from Hydaelyn, but from other planets/stars end up.