Scientists recently discovered an extrasolar planet in a triple-star system.  Previously thought impossible due to competing gravitational forces, the discovery challenges current planet formation theories.

Located in the triple-star system labeled HD 188753 some 149 light-years away in the constellation Cygnus, the newfound planet is a gas giant slightly larger than Jupiter.  Observation indicates it speeds around its central star in a 3.5-day orbit.

Current planet formation theories indicate that giant planets, like the one discovered here, can only form in more stable environments and much further from their central star than this planet.  Applying our current understanding of planetary formation would indicate this planet is impossible because the stellar pair circling the central star likely sheared off much of the planet making material in the disk that would have existed around the primary star in its youth.  This material, a proto-planetary disk, is the basis of the construction materials needed for planets.  That being the case, there was no safe place for this world to have formed.

Yet there it is.

Maciej Konacki from the California Institute of Technology discovered the far-off world during his search of nearly 500 distant star systems for extrasolar planets.  When asked about the seeming disparity between this planet and current formation theories, Konacki said, “How that planet formed in such a complicated setting is very puzzling.  I believe there is yet much to be learned about how giant planets are formed.”