arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0807.3746astro-ph
收藏

T-Lyr1-17236:一个长周期低质量双星

T-Lyr1-17236: A Long-Period Low-Mass Eclipsing Binary

Jonathan Devor, David Charbonneau, Guillermo Torres, Cullen H. Blake, Russel J. White, Markus Rabus, Francis T. O'Donovan, Georgi Mandushev, Gaspar Bakos, Gabor… 展开作者

Jonathan Devor, David Charbonneau, Guillermo Torres, Cullen H. Blake, Russel J. White, Markus Rabus, Francis T. O'Donovan, Georgi Mandushev, Gaspar Bakos, Gabor Furesz, Andrew Szentgyorgyi

摘要:

我们描述了一个0.68+0.52太阳质量食双星(EB)的发现与8.4天的轨道周期,发现通过系统搜索跨大西洋系外行星调查(TrES)的10个领域。这种长周期的低质量EB构成了解决主序列底部理论和观测质量-半径关系之间长期存在的差异的关键测试案例。有人认为,这种差异可能与强恒星磁场有关,而在目前的理论模型中,这一点没有得到适当的解释。所有先前特征良好的低质量主序EB的周期为几天或更短,因此,它们的组成部分预计将作为潮汐同步的结果快速旋转,从而产生强磁场。相比之下,这里描述的双星系统的周期比以前描述的低质量主序EB长三倍以上,其组成部分旋转相对较慢。因此,预计它将有一个较弱的磁场,并更好地匹配理论恒星模型的假设。我们的后续观察,这EB产生初步的恒星性质,这表明它确实是符合目前的模型。如果进一步的观测证实这个系统的活动水平较低,这些测定将为质量半径差异至少部分是由于磁场活动的假设提供支持。

英文摘要:

We describe the discovery of a 0.68+0.52 solar mass eclipsing binary (EB) with an 8.4-day orbital period, found through a systematic search of ten fields of the Trans-atlantic Exoplanet Survey (TrES). Such long-period low-mass EBs constitute critical test cases for resolving the long standing discrepancy between the theoretical and observational mass-radius relations at the bottom of the main sequence. It has been suggested that this discrepancy may be related to strong stellar magnetic fields, which are not properly accounted for in current theoretical models. All previously well-characterized low-mass main sequence EBs have periods of a few days or less, and their components are therefore expected to be rotating rapidly as a result of tidal synchronization, thus generating strong magnetic fields. In contrast, the binary system described here has a period that is over three times longer than previously characterized low-mass main sequence EBs, and its components rotate relatively slowly. It is therefore expected to have a weaker magnetic field and to better match the assumptions of theoretical stellar models. Our follow-up observations of this EB yield preliminary stellar properties that suggest it is indeed consistent with current models. If further observations confirm a low level of activity in this system, these determinations would provide support for the hypothesis that the mass-radius discrepancy is at least partly due to magnetic activity.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑