Hydrodynamic simulations of cool stellar atmospheres with MANCHA

 

 

Perdomo García, A., Vitas, N., Khomenko, E., Collados, M., A&A, 688, A27 (2024)

arxiv

Three-dimensional simulations do much more than reproduce what we observe on stellar surfaces. They give us a unique laboratory in which we can experiment with stellar atmospheres: change the physical ingredients, follow their interaction, and understand how convection, radiation and atmospheric structure are connected.

In this paper, we used the MANCHA code to simulate the atmospheres of three cool main-sequence stars, G2V, K0V and M2V, and explored one particularly important ingredient: radiative transfer and opacity. We tested how different approximations to the enormously complex stellar opacity affect radiative energy exchange and, ultimately, the atmospheric structure.

The results show how increasingly important a realistic treatment of opacity becomes as we move toward cooler stars, where molecules start to dominate the radiative properties of the atmosphere.

Another important piece of Andrea’s PhD work, and another step toward realistic 3D modelling across the cool-star sequence.