Juldice was a planet in the Rishi Maze Satellite Galaxy that was the ancestral home of the Celestials 5 billion years before the dawn of the republic. By the time of the Clone Wars, Juldice's parent star Aspan had long since died, leaving behind a white dwarf, which the devastated planet Juldice continued to orbit.
Life developed on Juldice within two billion years. It was one of relatively few planets to experience abiogenesis, where life created itself from inorganic chemicals.
The Celestials developed from complex multicellular organisms within 2 billion years, becoming sentient around 5,000,000,000 BBY. The Celestials became a spacefaring civilization shortly after, eventually making their way from the Rishi Maze to the Galaxy proper. Since their planet (and the life on it) formed so incredibly early, they were the only spacefaring civilization in the Galaxy.
The Celestials and eventually abandoned their original homeworld, having adapted to living in space over thousands of years, and no longer needing a planet to support them. Juldice continued to support complex life for more than three billion years after the Celestials left, before it's parent star became hot and bright enough to extinguish almost all life on the planet.
The star died in approximately 500,000,000 BBY, leaving a white dwarf. The planet Juldice would continue to orbit the white dwarf, and still existed in it's physical form long after the Clone Wars.