Hi RL

One quote from the article about Gabrielle...

Gabrielle is 60 to 100 times fainter than Xena and orbits the planet once every 14 days. The orbit of the moon will help astronomers pin down Xena's exact mass.

"A combination of the distance of the moon from the planet and the speed it goes around the planet tells you very precisely what the mass of the planet is," Brown said in a statement released by the California Institute of Technology. "If the planet is very massive, the moon will go around very fast; if it is less massive, the moon will travel more slowly."

...so do they have a period yet and just not an orbital radius?

Adam