During most of their life, stars fuse hydrogen into helium in their cores. The mixing of chemical elements in the radiative envelope of stars with a convective core is able to replenish the core with extra fuel. If effective, such deep mixing allows stars to live longer and change their evolutionary path. Yet localized observations to constrain internal mixing are absent so far. Gravity modes probe the deep stellar interior near the convective core and allow us to calibrate internal mixing processes. Here we provide core-to-surface mixing profiles inferred from observed dipole gravity modes in 26 rotating stars with masses between 3 and 10 solar masses. We find a wide range of internal mixing levels across the sample. Stellar models with stratified mixing profiles in the envelope reveal the best asteroseismic performance. Our results provide observational guidance for three-dimensional hydrodynamical simulations of transport processes in the deep interiors of stars.

在它们生命的大部分时间里，恒星在其核心将氢融合成氦。恒星辐射包层中的化学元素与对流核心的混合能够为核心补充额外的燃料。如果有效，这种深度混合可以让恒星寿命更长并改变它们的进化路径。然而，到目前为止，还没有限制内部混合的局部观察。重力模式探测对流核心附近的深层恒星内部，并允许我们校准内部混合过程。在这里，我们提供了从 26 颗质量在 3 到 10 个太阳质量之间的旋转恒星中观察到的偶极重力模式推断的核心到表面混合剖面。我们在样本中发现了广泛的内部混合水平。在包络线中具有分层混合剖面的恒星模型揭示了最佳的星震性能。