Since the discovery of the first planet outside the solar system in 1995, the detection of exoplanets has been an attractive and engaging scientific field. This article intends to present briefly the radial velocity method for detecting the presence of an unseen planet orbiting a star. Based on an experimental setup, the presentation resorts to the analogy between sound waves and light waves. In particular, they can undergo the Doppler effect from which the radial velocity can be determined. Because the Doppler effect is easier to observe for sound waves than for light waves, a Bluetooth speaker simulates a star. It rotates in a horizontal circle with a constant angular speed, while emitting at two user-selected frequencies, simulating two spectral lines of a star. From the analysis of spectrograms, the radial velocities are deduced. Very good agreement is found between the experiment and theory.

中文翻译：

---

圆周运动声源的径向速度，用于说明系外行星的探测

自 1995 年发现第一颗太阳系外行星以来，系外行星的探测一直是一个有吸引力且引人入胜的科学领域。本文旨在简要介绍径向速度方法，用于检测围绕恒星运行的不可见行星的存在。基于实验设置，演示采用声波和光波之间的类比。特别是，它们可以经受多普勒效应，从中可以确定径向速度。因为声波比光波更容易观察到多普勒效应，所以蓝牙音箱模拟了一颗星星。它以恒定角速度在水平圆圈中旋转，同时以用户选择的两个频率发射，模拟恒星的两条谱线。从光谱图的分析中，可以推导出径向速度。