Giant Fast-moving Planet Discovered

Those exoplanetary scientists sure have their hands full these days.

Just days after Geoff Marcy and his crew announced some new planets, the XO Project, a joint team made up of amateurs and pro astronomers have announced a new planet that's 13 times the size of Jupiter, but whizzes around its orbit in under four days.

But the planet, named XO-3b, might actually be a brown dwarf, explains Space.com:

Brown dwarfs are too massive to be considered planets, yet they don't meet the "Sumo-weight" requirements for hydrogen fusion
(about 80 Jupiters) so they fall short of being stars. The new object's mass is right on the boundary where brown-dwarf status begins, a mass requirement for the burning of deuterium, or heavy hydrogen.

"The controversy lies at the lower end of the scale," said [Christopher Johns-Krull, an astronomer at Rice University.]
"Some people believe anything capable of fusing deuterium, which in theory happens around 13 Jupiter masses, is a brown dwarf. Others say it's not the mass that matters, but whether the body forms on its own or as part of a planetary system."

Image credit: Rice University