article published yes Nils B. De Vries author Arthur Le Saux author Isabelle Baraffe author Thomas Guillet author Richard H.D. Townsend author Armand Leclerc author 2a1fb1fc-f373-11ef-901a-87cee43a1217 Adrien Morison author LiBu department Unveiling the mysteries of stellar dynamics: a pioneering journey in magnetoasteroseismology project Mixed modes are observed in many low-mass evolved stars. They provide information about core rotation rates of these stars, which are lower than predicted by stellar evolution models. The mixed modes themselves have been invoked as an angular momentum (AM) transport mechanism, but estimating their transport efficiency requires knowledge of their amplitudes. We constrain, for the first time, the mixed-mode amplitudes in 2D hydrodynamical simulations of a 1.3M⊙ red giant using the code MUSIC. We perform two simulations with outer radial truncations at fractional radii ro/r⋆ = 0.90 and 0.98. We compare the modes in the simulation with those found using both GYRE and a Dedalus eigenvalue solver. Excellent frequency agreement is found for all p-dominated modes, with minor discrepancies for g-dominated modes, especially in the frequency range [60, 240] μHz. We find excellent eigenfunction agreement for all modes except those in this frequency range. According to empirical predictions, the largest kinetic energies are located around Vmax= 312.μHz, but in both simulations, the modes with frequencies of ν < 50 μHz have the largest kinetic energies. In the simulation with r/r⋆ = 0.98, the simulated modes have extrapolated surface velocities comparable to the empirical predictions, with the highest surface velocities in a bell-shaped curve peaking around ν = 700 μHz. The extrapolated surface velocities of the low-frequency modes are small and thus hard to observe, but their large kinetic energies deeper in the interior could significantly impact AM transport, which has not yet been investigated. https://research-explorer.ista.ac.at/download/22262/22275/2026_AstrophysicalJour_deVries.pdf application/pdfno IOP Publishing2026 eng Stellar physicsStellar interiorsAsteroseismologyStellar oscillationsHydrodynamical simulations 0004-637X 1538-4357 2606.0712510.3847/1538-4357/ae7a3c 10052 De Vries, N. B., Le Saux, A., Baraffe, I., Guillet, T., Townsend, R. H. D., Leclerc, A., &#38; Morison, A. (2026). Revealing mixed modes in compressible hydrodynamical simulations of red giant stars. <i>The Astrophysical Journal</i>. IOP Publishing. <a href="https://doi.org/10.3847/1538-4357/ae7a3c">https://doi.org/10.3847/1538-4357/ae7a3c</a> De Vries, Nils B., Arthur Le Saux, Isabelle Baraffe, Thomas Guillet, Richard H.D. Townsend, Armand Leclerc, and Adrien Morison. “Revealing Mixed Modes in Compressible Hydrodynamical Simulations of Red Giant Stars.” <i>The Astrophysical Journal</i>. IOP Publishing, 2026. <a href="https://doi.org/10.3847/1538-4357/ae7a3c">https://doi.org/10.3847/1538-4357/ae7a3c</a>. De Vries NB, Le Saux A, Baraffe I, Guillet T, Townsend RHD, Leclerc A, Morison A. 2026. Revealing mixed modes in compressible hydrodynamical simulations of red giant stars. The Astrophysical Journal. 1005(2), 154. N.B. De Vries, A. Le Saux, I. Baraffe, T. Guillet, R.H.D. Townsend, A. Leclerc, A. Morison, The Astrophysical Journal 1005 (2026). De Vries, Nils B., et al. “Revealing Mixed Modes in Compressible Hydrodynamical Simulations of Red Giant Stars.” <i>The Astrophysical Journal</i>, vol. 1005, no. 2, 154, IOP Publishing, 2026, doi:<a href="https://doi.org/10.3847/1538-4357/ae7a3c">10.3847/1538-4357/ae7a3c</a>. De Vries NB, Le Saux A, Baraffe I, et al. Revealing mixed modes in compressible hydrodynamical simulations of red giant stars. <i>The Astrophysical Journal</i>. 2026;1005(2). doi:<a href="https://doi.org/10.3847/1538-4357/ae7a3c">10.3847/1538-4357/ae7a3c</a> N. B. De Vries <i>et al.</i>, “Revealing mixed modes in compressible hydrodynamical simulations of red giant stars,” <i>The Astrophysical Journal</i>, vol. 1005, no. 2. IOP Publishing, 2026. 222622026-07-12T22:02:17Z2026-07-13T08:16:25Z