To investigate statistically whether magnetic fields in massive stars are ubiquitous or appear in stars with specific spectral classification, certain ages, or in a special environment, we acquired 41 new spectropolarimetric observations for 36 stars. Among the observed sample roughly half of the stars are probable members of clusters at different ages, whereas the remaining stars are field stars not known to belong to any cluster or association.
Spectropolarimetric observations were obtained during three different nights using the low-resolution spectropolarimetric mode of FORS2 (FOcal Reducer low dispersion Spectrograph) mounted on the 8-m Antu telescope of the VLT. To assess the membership in open clusters and associations, we used astrometric catalogues with the best currently available kinematic and photometric data.
A field at a significance level of 3sigma was detected in ten O-type stars. Importantly, the largest longitudinal magnetic fields were measured in two Of?p stars: <B_z>=-381+-122G for CPD-282561 and <B_z>=-297+-62G for HD148937, previously detected by us as magnetic. The obtained observations of HD148937 on three different nights indicate that the magnetic field is slightly variable. Our new measurements support our previous conclusion that large-scale organized magnetic fields with polar field strengths in excess of 1kG are not widespread among O-type stars. Among the stars with a detected magnetic field, only one star, HD156154, belongs to an open cluster at high membership probability. According to previous kinematic studies, four magnetic O-type stars in the sample are well-known candidate runaway stars.
Constraining general massive-star physics by exploring the unique properties of magnetic O-stars: Rotation, macroturbulence, and sub-surface convection
Detailed Simulations of Massive Hierarchical Triple Star Systems - Exploring the impact of the stellar physics on the evolutionary pathways of massive hierarchical triple systems
The fates of massive stars: exploring uncertainties in stellar evolution with METISSE
在先进的电磁波和引力波探测器时代，有效结合和研究恒星演化对双星和恒星动力学系统的影响变得越来越重要。系统的研究致力于探索恒星演化中的不确定参数，以解释最近对恒星星族的观测。我们提出了一种新的方法，常用的单星进化（SSE）拟合公式，一个更适应：单星进化插值方法（METISSE）。它利用预先计算的恒星轨道集之间的插值来近似恒星种群的演化参数。我们已经使用METISSE与详细的恒星轨道计算的恒星天体物理学实验模块（MESA），波恩进化代码（BEC）和剑桥星代码。与SSE相比，METISSE更好地再现了使用STARS代码计算的恒星轨迹，并且平均快三倍。使用MESA和BEC计算的恒星轨迹，我们应用METISSE探索大质量恒星的残余质量，最大径向膨胀和主序星寿命的差异。我们发现，恒星演化中使用的不同物理成分，例如辐射主导的包络的处理，可以影响它们的演化结果。对于质量范围在9到100 M $_\odot$的恒星，残余质量的预测可以相差20 M $_\odot$，而恒星所达到的最大径向膨胀在不同的恒星模型之间可以相差一个数量级。
