Thursday, March 03, 2022, 16:00
online only
(for the zoom link contact michael.spira@psi.ch, johannes.schlenk@psi.ch or
antonio.coutinho@psi.ch)
Caroline Dorn, University of Zürich
Abstract:
I will demonstrate that the deep volatile storage capacity of magma
oceans has significant implications for the bulk composition, interior
and climate state inferred from exoplanet mass and radius data.
Experimental petrology provides the fundamental properties on the
ability of water and melt to mix. So far, these data have been largely
neglected for exoplanet mass-radius modeling. Here, I present an
advanced interior model for water-rich rocky exoplanets. The new model
allows us to test the effects of rock melting and the redistribution of
water between magma ocean and atmosphere on calculated planet radii.
Models with and without rock melting and water partitioning lead to
deviations in planet radius of up to 16 % for a fixed bulk composition
and planet mass. This is within current accuracy limits for individual
systems and statistically testable on a population level. Unrecognized
mantle melting and volatile redistribution in retrievals may thus
underestimate the inferred planetary bulk water content by up to one
order of magnitude.