近日，比利时鲁汶大学天文学研究所的A. J. Frost及其研究团队取得一项新进展。经过不懈努力，他们发现一颗磁性大质量恒星经历过一次恒星合并。相关研究成果已于
该研究团队使用多历元干涉和光谱观测表征了HD 148937，这是一个由两颗大质量恒星组成的双星系统。研究人员发现只有一颗恒星是磁性的，而且它看起来比它的伴星更年轻。该系统的特性和周围的双极星云可以用两颗恒星合并(在先前的三重系统中)，产生磁性大质量恒星的模型来重现。
这一研究结果提供了观测证据，证明至少在一些大质量恒星中，磁场是通过恒星合并形成的。
据悉，大质量恒星(形成时质量≥8倍太阳质量的恒星)的辐射包层无法维持发电机效应，而发电机是低质量恒星产生磁场的机制。尽管如此，大约7%的大质量恒星观测到磁场，其起源仍有争议。
附：英文原文
Title: A magnetic massive star has experienced a stellar merger
Author: A. J. Frost, H. Sana, L. Mahy, G. Wade, J. Barron, J.-B. Le Bouquin, A. Mérand, F. R. N. Schneider, T. Shenar, R. H. Barbá, D. M. Bowman, M. Fabry, A. Farhang, P. Marchant, N. I. Morrell, J. V. Smoker
Issue&Volume: 2024-04-12
Abstract: Massive stars (those ≥8 solar masses at formation) have radiative envelopes that cannot sustain a dynamo, the mechanism that produces magnetic fields in lower-mass stars. Despite this, approximately 7% of massive stars have observed magnetic fields, the origin of which is debated. We used multi-epoch interferometric and spectroscopic observations to characterize HD 148937, a binary system of two massive stars. We found that only one star is magnetic and that it appears younger than its companion. The system properties and a surrounding bipolar nebula can be reproduced with a model in which two stars merged (in a previous triple system) to produce the magnetic massive star. Our results provide observational evidence that magnetic fields form in at least some massive stars through stellar mergers.
Source: https://www.science.org/doi/10.1126/science.adg7700