Planetary systems in mean motion resonances hold a special place among the planetary population. They allow us to study planet formation in great detail as dissipative processes are thought to have played an important role in their existence. Additionally, planetary masses in bright resonant systems can be independently measured via both radial velocities and transit timing variations. In principle, they also allow us to quickly determine the inclination of all planets in the system since, for the system to be stable, they are likely all in coplanar orbits. To describe the full dynamical state of the system, we also need the stellar obliquity, which provides the orbital alignment of a planet with respect to the spin of its host star and can be measured thanks to the Rossiter–McLaughlin effect. It was recently discovered that HD 110067 harbors a system of six sub-Neptunes in resonant chain orbits. We here analyze an ESPRESSO high-resolution spectroscopic time series of HD 110067 during the transit of planet c. We find the orbit of HD 110067 c to be well aligned, with a sky-projected obliquity of λ =6^{+24_{-26 deg. This result indicates that the current architecture of the system was reached through convergent migration without any major disruptive events. Finally, we report transit-timing variation in this system as we find a significant offset of 19 ± 4 min in the center of the transit compared to the published ephemeris.}}

中文翻译：

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HD 110067 c 具有对齐轨道


平均运动共振的行星系统在行星群体中占有特殊的地位。它们使我们能够详细研究行星的形成，因为耗散过程被认为在行星的存在中发挥了重要作用。此外，明亮共振系统中的行星质量可以通过径向速度和凌日时间变化来独立测量。原则上，它们还使我们能够快速确定系统中所有行星的倾角，因为为了使系统稳定，它们很可能都在共面轨道上。为了描述系统的完整动态状态，我们还需要恒星倾角，它提供了行星相对于其主恒星自转的轨道排列，并且可以通过罗西特-麦克劳林效应进行测量。最近发现HD 110067在共振链轨道上拥有一个由六个亚海王星组成的系统。我们在这里分析了 c 行星凌日期间 HD 110067 的 ESPRESSO 高分辨率光谱时间序列。我们发现 HD 110067 c 的轨道排列良好，天空投影倾角为 λ =6 ^{+24_{-26 deg. This result indicates that the current architecture of the system was reached through convergent migration without any major disruptive events. Finally, we report transit-timing variation in this system as we find a significant offset of 19 ± 4 min in the center of the transit compared to the published ephemeris.}}