Unconventional Exoplanet Defies Orbital Norms

The planetary system WASP-131 has a gas planet, 131b, with an unusual orbit that is tilted about 160 degrees from the rotational plane of the star, making it a high, almost polar retrograde orbit. The mechanism behind the odd orbit isn't clear, but it follows a pattern seen with many hot gas exoplanets. About a quarter of them have significantly tilted orbits. One possibility is the Kozai effect, while another is a magnetic interaction between the planet and the protoplanetary disk early in its formation period.