Numerical simulations have shown that the strength of planetary magnetic fields depends on the convective energy flux emerging from planetary interiors. Here we model the interior structure of gas giant planets using MESA, to determine the convective energy flux that can drive the generation of magnetic field. This flux is then incorporated in the Christensen et al. dynamo formalism to estimate the maximum dipolar magnetic field of our simulated planets.
First, we explore how the surface field of intensely irradiated hot Jupiters ( 300 Earth Masses) and hot Neptunes ( 20 Earth Masses) evolve as they age. Assuming an orbital separation of 0.1 au, for the hot Jupiters, we find that the maximum surface magnetic field evolves from 240 G at 500 Myr to 120 G at 5 Gyr. For hot Neptunes, the magnetic field evolves from 11 G at young ages and dies out at ≳2 Gyr.
Furthermore, we also investigate the effects of atmospheric mass fraction, atmospheric evaporation, orbital separations αand additional planetary masses on the derived maximum surface field. We found that it increases with αfor very close-in planets and plateaus out after that. Higher atmospheric mass fractions lead in general to stronger surface fields, because they allow for more extensive dynamo regions and stronger convection.
Finally, we show that potential auroral emission from hot Jupiters and very young hot Neptunes could be detectable with ground-based radio observatories.
@article{exomag24,title={Magnetic fields of hot Jupiters and hot Neptunes: Evolution and Detection Prospects},author={Kilmetis, K. and Vidotto, A. A. and Allan, A. and Kubyshkina, D.},year={2024},publisher={Monthly Notices of the Royal Astronomical Society},}
In Prep
Black Hole Brunch
K.
Kilmetis, P.
Martire, E. M.
Rossi
, and
2 more authors
This is currently under prep but it should be aroound soon enough.
@article{tde24,title={Black Hole Brunch},author={Kilmetis, K. and Martire, P. and Rossi, E. M. and Steinberg, E. and Stone, N. C.},year={2024},publisher={Monthly Notices of the Royal Astronomical Society},}