"Hot Jupiters" are believed to have the ability to make the Sun wobble.
Cornell researchers found that when these large gaseous planets wind their way through their own solar systems they have an effect on their host suns.
"Although the planet's mass is only one-thousandth of the mass of the sun, the stars in these other solar systems are being affected by these planets and making the stars themselves act in a crazy way," said Dong Lai, Cornell professor of astronomy and senior author on the research.
In our own solar system the Sun's rotation axis is approximately aligned with the orbital axis of the other planets. The orbital axis is perpendicular to the flat plane in which planets perform their revolution around the Sun. In systems with hot Jupiters the orbital axis of these planets is actually misaligned with the rotation axis with the rotation axis of the host star. In recent years researchers have wondered why the spin-orbit was misaligned between stars and planets.
Hot Jupiters tend to orbit extremely close to their host stars and influence their gravity and cause them to fall into unusual orbits.
"When exoplanets were first found in the 1990s, it was large planets like Jupiter that were discovered. It was surprising that such giant planets can be so close to parent star," Lai said. "Our own planet Mercury is very close to our sun. But these hot Jupiters are much closer to their suns than Mercury."
The team simulated the dynamics of the exotic planetary systems the team demonstrated that as the Jupiter-like planet approaches its host star it can force the spin axis to change its orientation.
"Also, it can make the star's spin axis change direction in a rather complex -- or even a chaotic -- way," said Lai. "This provides a possible explanation to the observed spin-orbit misalignments, and will be helpful for understanding the origin of these enigmatic planets."
