Thermal evolution of Lava planets and their dependency on mass and Core Mass Fractions

Mahesh Herath ( Université McGill )

Rocky planets in extremely tight orbits around their host stars experience equilibrium temperatures more than 1000 K, melting their surfaces and creating a magma ocean. The unknown depths of magma oceans in these lava planets could have a leading order impact on near term JWST observations including thermal phase variations and degassed atmospheres. We use time dependent 2-box and 3-box models to simulate thermal evolution from the fully molten mantle of a young lava planet to a partially molten steady state mantle. These models account for the convective and conductive heat transport in the rocky interior, as well as boundary layers between the different phases. The models can also be adapted to the asymmetric geometry of lava planets, with a dayside magma ocean and a cold, solidified nightside mantle. I will present results from our baseline model and discuss how planetary mass and core mass fraction impacts the thermal evolution of lava planets.