论文标题
超短期超级地点的测量的自旋轨道对齐55 cancri e
Measured Spin-Orbit Alignment of Ultra-Short Period Super-Earth 55 Cancri e
论文作者
论文摘要
行星的轨道对齐对行星的形成和随之而来的如何发展对重要的限制。超短暂时期行星的主要地层途径（$ p <1美元）特别神秘，因为这样的行星最有可能进一步形成，而且还不太了解是什么使他们的迁移向内迁移到当前的位置。对于较小的超级收获/亚新持久行星，难以测量轨道对齐，这会产生较小的振幅信号。在这里，我们提出了55个cancri e的两个转运的径向速度，这是一个超短期的超级地球，观察到了极端精确的光谱仪（Expres）。使用经典的Rossiter-McLaughlin（RM）方法，我们测量55个CNC E的天空旋转旋转轨道对准（即，行星的轨道轴及其宿主星形的旋转轴之间的投影角度为$λ= 10 \ setack = 10 \ orperack { $ψ= 23 \替代{+14 \\ -12}^{\ circ} $。 ExpRes数据的最佳拟合RM模型的径向速度半振幅仅为$ 0.41 \ setack {+0.09 \\ -0.10} M S^{ - 1} $。 55 CNC E的自旋轨道对齐有利于超短期行星动态柔和的迁移理论，即通过低含量的行星 - 行星 - 行星 - 行星相互作用和/或行星倾斜潮汐进行潮汐耗散。
A planet's orbital alignment places important constraints on how a planet formed and consequently evolved. The dominant formation pathway of ultra-short period planets ($P<1$ day) is particularly mysterious as such planets most likely formed further out, and it is not well understood what drove their migration inwards to their current positions. Measuring the orbital alignment is difficult for smaller super-Earth/sub-Neptune planets, which give rise to smaller amplitude signals. Here we present radial velocities across two transits of 55 Cancri e, an ultra-short period Super-Earth, observed with the Extreme Precision Spectrograph (EXPRES). Using the classical Rossiter-McLaughlin (RM) method, we measure 55 Cnc e's sky-projected stellar spin-orbit alignment (i.e., the projected angle between the planet's orbital axis and its host star's spin axis) to be $λ=10\substack{+17\\ -20}^{\circ}$ with an unprojected angle of $ψ=23\substack{+14\\ -12}^{\circ}$. The best-fit RM model to the EXPRES data has a radial velocity semi-amplitude of just $0.41\substack{+0.09\\ -0.10} m s^{-1}$. The spin-orbit alignment of 55 Cnc e favors dynamically gentle migration theories for ultra-short period planets, namely tidal dissipation through low-eccentricity planet-planet interactions and/or planetary obliquity tides.
