Satellites orbiting disk galaxies can induce phase space features such as spirality, vertical heating and phase-mixing in their disks. Such features have also been observed in our own Galaxy, but the complexity of the Milky Way disk has only recently been fully mapped by Gaia Data Release 2 (DR2) data. This complex behaviour is mainly ascribed to repeated perturbations induced by the Sagittarius dwarf galaxy (Sgr) along its orbit, pointing to this satellite as the main dynamical architect of the Milky Way disk. Here, we model Gaia DR2-observed colour–magnitude diagrams to obtain a detailed star formation history of the ~2 kpc bubble around the Sun. It reveals three conspicuous and narrow episodes of enhanced star formation that we can precisely date as having occurred 5.7, 1.9 and 1.0 Gyr ago. The timing of these episodes coincides with proposed Sgr pericentre passages according to (1) orbit simulations, (2) phase space features in the Galactic disk and (3) Sgr stellar content. These findings most probably suggest that Sgr has also been an important actor in the build-up of the stellar mass of the Milky Way disk, with the perturbations from Sgr repeatedly triggering major episodes of star formation.

绕圆盘星系运行的卫星会在其圆盘中诱发相空间特征，例如螺旋度，垂直加热和相混合。在我们自己的Galaxy中也观察到了这些功能，但是银河系磁盘的复杂性直到最近才由Gaia Data Release 2（DR2）数据完全映射。这种复杂的行为主要归因于人马座矮星系（Sgr）沿其轨道所引起的反复扰动，这表明该卫星是银河系盘的主要动力设计师。在这里，我们对Gaia DR2观察到的色度图进行建模，以获取太阳周围〜2 kpc气泡的详细恒星形成历史。它揭示了三个明显的，狭窄的增强恒星形成过程，我们可以准确地将它们定为发生在5.7、1.9和1.0 Gyr之前。这些事件的发生时间与根据（1）轨道模拟，（2）Galactic盘中的相空间特征和（3）Sgr恒星含量建议的Sgr中心点通过相吻合。这些发现最有可能表明，Sgr也是银河系恒星质量增加的重要参与者，Sgr的扰动反复触发了恒星形成的主要事件。