What does observing a Hot Jupiter in a 'retrograde' or 'wrong-way' orbit imply about its past?

Answer

That the inward migration involved a major dynamical event, possibly flipping its angular momentum

A retrograde orbit, where the planet orbits opposite to the star's rotation, suggests a violent gravitational interaction flipped the planet's angular momentum.

What does observing a Hot Jupiter in a 'retrograde' or 'wrong-way' orbit imply about its past?

#Videos

Hot Jupiter Study - YouTube

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