Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, Camperdown, New South Wales, Australia.
Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark.
Nature. 2020 May;581(7807):147-151. doi: 10.1038/s41586-020-2226-8. Epub 2020 May 13.
Asteroseismology probes the internal structures of stars by using their natural pulsation frequencies. It relies on identifying sequences of pulsation modes that can be compared with theoretical models, which has been done successfully for many classes of pulsators, including low-mass solar-type stars, red giants, high-mass stars and white dwarfs. However, a large group of pulsating stars of intermediate mass-the so-called δ Scuti stars-have rich pulsation spectra for which systematic mode identification has not hitherto been possible. This arises because only a seemingly random subset of possible modes are excited and because rapid rotation tends to spoil regular patterns. Here we report the detection of remarkably regular sequences of high-frequency pulsation modes in 60 intermediate-mass main-sequence stars, which enables definitive mode identification. The space motions of some of these stars indicate that they are members of known associations of young stars, as confirmed by modelling of their pulsation spectra.
天文地震学通过利用恒星的自然脉动频率来探测其内部结构。它依赖于识别可以与理论模型进行比较的脉动模式序列，对于许多类脉动体，包括低质量太阳型恒星、红巨星、高质量恒星和白矮星，已经成功地进行了这一工作。然而，大量中等质量的脉动恒星——所谓的δ Scuti 恒星——具有丰富的脉动光谱，迄今为止还不可能进行系统的模式识别。这是因为只有看似随机的一组可能的模式被激发，而且快速旋转往往会破坏规则模式。在这里，我们报告了在 60 颗中等质量主序星中探测到高频脉动模式的显著规则序列，这使得能够进行明确的模式识别。这些恒星中的一些的空间运动表明它们是已知年轻恒星星团的成员，这通过对它们的脉动光谱进行建模得到了证实。
