<p><strong>Abstract</strong></p>
<p>The Juno spacecraft is providing measurements of Jupiter's gravity field with an outstanding level of accuracy [3], leading to better constraints on the interior of Jupiter. Improving our knowledge of the internal structure of Jupiter is key, to understand the formation and the evolution of the planet [5,6] but also in the framework of exoplanets exploration. Hence, developing interiors models of Jupiter which are consistent with the observations is essential.</p>
<p>Models of giant planets' internal structure are built with the code CEPAM [2] to compute the gravitational moments <em>J<sub>2n</sub></em> [1] and compare them to the observational values. As the numerical calculation of the gravitational moments is crucial, we are here using a fast method based on a 4th order development of the Theory of Figures, coupled with the more precise CMS (Concentric MacLaurin Spheroid) method. This allows us to obtain reliable values of <em>J<sub>2n</sub></em> in a reasonable amount of time.</p>
<p>MCMC (Markov chain Monte Carlo) simulations are then run to study a wide range of interior models, using the above way to compute the gravitational moments. This bayesian approach leads to a broad investigation of the parameters range such as the chemical abundances, the 1 bar temperature or the transition pressure between the molecular hydrogen and metallic hydrogen layers.</p>
<p>Important questions remain to be clarified like the distribution and amount of the heavy elements inside giant planets, following the hypothesis of a gradual distribution of the heavy elements up to a certain fraction of Jupiter's radius [7]. Throughout this talk, I will pay particular attention on the equations of state used in our models [4]. Indeed, giant planets' internal structure seems strongly linked to the physical properties of its components and it is critical to assess how sensitive to the equations of state our models are.</p>
<p><strong>References</strong></p>
<p>[1] Guillot, T., Miguel, Y. et al.: A suppression of differential rotation in Jupiter's deep interior, Nature, Vol 555, pp. 227-230, (2018).</p>
<p>[2] Guillot, T. and Morel, P.: CEPAM: a code for modeling the interiors of giant planets, Astronomy and Astrophysics Supplement Series 109, 109-123 (1995)</p>
<p>[3] Iess, L. et al.: Measurement of Jupiter's asymmetric gravity field, Nature, Vol 555, pp. 220-222, (2018).</p>
<p>[4] Miguel, Y., Guillot, T. et al.: Jupiter internal structure: the effect of different equations of state. Astron. Astrophys. 596, A114 (2016)</p>
<p>[5] Vazan, A., Helled, R. and Guillot, T.: Jupiter's evolution with primordial composition gradients. Astron. Astrophys. 610, L14 (2018).</p>
<p>[6] Venturini, J., Helled, R.: Jupiter's heavy-element enrichment expected from formation models. Astron. Astrophys. 634, A31 (2020).</p>
<p>[7] Wahl, S. M. et al.: Comparing Jupiter interior structure models to Juno gravity measurements and the role of a dilute core, Geophys. Res. Lett. Vol 44, pp. 4649-4659, (2017).</p>
Theory of low mass stars, brown dwarfs and extra-solar giant planets
