论文标题
相似但不同：ONFP/OEF星星的各种景观变化
Similar but different: the varied landscape of Onfp/Oef stars variability
论文作者
论文摘要
OEF类别会迅速旋转并进化出O-Star，显示出中央逆转的HE II 4686发射线。其光谱和风频谱线变异性的起源是有争议的，旋转调制或脉动是主要的竞争者。为了对这个问题开发新的启示，我们分析了五个OEF星的高质量和高质苔丝光度法时间序列。我们还为一个目标（Lambda CEP）收集了一个新的时间序列，这是过去几年的特定辩论的主题。这些观察结果揭示了OEF行为的多样性。虽然基于空间的光度数据揭示了所有目标中的大量红噪声组件，但只有Zeta Pup似乎显示出长期寿命的周期性。在我们的样品中，恒星在低频处表现出显性信号，但看起来相对短暂。这让人联想到瞬态光谱斑点旋转调制，尽管这种情况受到HD 14442的情况的挑战，HD 14442的情况下，其1.230 d $^{ - 1} $信号显着超过了关键的旋转频率。同时，在恒星的光度法或光谱中没有发现持续的p模式非脉冲的证据，只有G模式脉动的暂时激发才能为主要信号提供另一种解释。最后，使用Gaia-Dr2的恒星进行了修订的灯光表明，它们并不都是Zeta Pup的超级巨人。然后出现了问题，而OEF特殊性毕竟表示一类均类的对象。
The Oef category gathers rapidly rotating and evolved O-stars displaying a centrally reversed He II 4686 emission line. The origin of the variability of their photospheric and wind spectral lines is debated, with rotational modulation or pulsations as the main contenders. To shed new light on this question, we analysed high-quality and high-cadence TESS photometric time series for five Oef stars. We also collected a new time series of spectra for one target (lambda Cep) which had been the subject of specific debates in the last years. These observations reveal the variety of Oef behaviours. While space-based photometric data reveal substantial red noise components in all targets, only zeta Pup seems to display a long-lived periodicity. In our sample, stars exhibit a dominant signal at low frequencies but it appears relatively short-lived. This is reminiscent of rotational modulations by transient photospheric spots, though this scenario is challenged by the case of HD 14442, whose 1.230 d$^{-1}$ signal significantly exceeds the critical rotational frequency. In parallel, no evidence of persistent p-mode non-radial pulsations is found in either photometry or spectroscopy of the stars, only temporary excitation of g-mode pulsations could offer an alternative explanation for the dominant signals. Finally, the revised luminosities of the stars using GAIA-DR2 show that they are not all supergiants as zeta Pup. The question then arises whether the Oef peculiarity denotes a homogeneous class of objects after all.
