Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, Victoria 3122, Australia.
ARC Centre of Excellence for Gravitational Wave Discovery, Hawthorn, Victoria 3122, Australia.
Science. 2022 Nov 11;378(6620):634-636. doi: 10.1126/science.abi9232. Epub 2022 Nov 10.
The fine structure constant α sets the strength of the electromagnetic force. The Standard Model of particle physics provides no explanation for its value, which could potentially vary. The wavelengths of stellar absorption lines depend on α but are subject to systematic effects owing to astrophysical processes in stellar atmospheres. We measured precise line wavelengths from observations of 17 stars, selected to have almost identical atmospheric properties to those of the Sun (solar twins), which reduces those systematic effects. We found that α varies by [Formula: see text] parts per billion within 50 parsecs from Earth. Combining the results from all 17 stars provides an empirical local reference for stellar measurements of α, with an ensemble precision of 12 parts per billion.
精细结构常数 α 决定了电磁力的强度。粒子物理学的标准模型并没有解释它的数值，这个数值可能会发生变化。恒星吸收线的波长取决于 α，但由于恒星大气中的天体物理过程，它们会受到系统效应的影响。我们通过对 17 颗恒星的观测测量了精确的谱线波长，这些恒星被选择为具有与太阳几乎相同的大气特性（太阳双胞胎），从而减少了这些系统效应。我们发现，在离地球 50 秒差距的范围内，α 的变化幅度为每十亿分之[Formula: see text]。综合所有 17 颗恒星的结果，为恒星对 α 的测量提供了一个经验本地参考，整体精度为每十亿分之 12。
