A Hot Polar Planet

Scientific American Blogs has picked up on our recent announcement of WASP-189b, an ultra-hot Jupiter transiting the bright A star HR 5599 in a polar orbit.

The host star, HR 5599, has a visual magnitude of V = 6.6, making it the brightest host star of a transiting hot Jupiter. The Scientific American piece, written by Caleb Scharf, focuses on the fact that the planet is in near-perfectly aligned polar orbit, saying:

“Like with other mis-aligned hot-Jupiter worlds, the big question is how does this situation arise? We don’t know for sure. One idea is that these planets have to form at larger distances from their stars and then migrate inwards — due to interactions either with a proto-planetary disk or other worlds, or both. Those interactions can also pump up the ellipticity of the orbit and its inclination. Later on the tidal forces between the planet and the star can pull it in close, but preserve a high orbital inclination…maybe.”

Credit: NASA, JPL, Caltech