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arXiv 2501.04523astro-ph.SRastro-ph.EP
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NGTS-EB-7:一个偏心、长周期、低质量食双星

NGTS-EB-7, an eccentric, long-period, low-mass eclipsing binary

Toby Rodel, Christopher. A. Watson, Solène Ulmer-Moll, Samuel Gill, Pierre F. L. Maxted, Sarah L. Casewell, Rafael Brahm, Thomas G Wilson, Jean C. Costes, Yoshi… 展开作者

Toby Rodel, Christopher. A. Watson, Solène Ulmer-Moll, Samuel Gill, Pierre F. L. Maxted, Sarah L. Casewell, Rafael Brahm, Thomas G Wilson, Jean C. Costes, Yoshi Nike Emilia Eschen, Lauren Doyle, Alix V. Freckelton, Douglas R. Alves, Ioannis Apergis, Daniel Bayliss, Francois Bouchy, Matthew R. Burleigh, Xavier Dumusque, Jan Eberhardt, Jorge Fernández Fernández, Edward Gillen, Michael R. Goad, Faith Hawthorn, Ravit Helled, Thomas Henning, Katlyn L. Hobbs, James S. Jenkins, Andrés Jordán, Alicia Kendall, Monika Lendl, James McCormac, Ernst J. W. de Mooij, Sean M. O'Brien, Suman Saha, Marcelo Tala Pinto, Trifon Trifonov, Stéphane Udry, Peter J. Wheatley

AI总结:

本文发现长周期高偏心食双星NGTS-EB-7 AB,测定其晚型M矮星次星的质量、半径与轨道参数,为检验完全对流M矮星演化模型提供关键基准。

摘要:

尽管晚型M矮星是银河系中最常见的恒星类型,但其物理性质往往约束较差。在食双星中,较早型的M矮星已观测到相对于演化模型的半径膨胀趋势,这可能由磁活动造成。目前尚不清楚这一趋势是否也延伸至对流边界以下的更晚型M矮星。因此,在食双星中发现质量更低、完全对流的M矮星,对于检验演化模型具有重要价值,尤其是在主星与伴星之间潮汐相互作用可忽略的较长周期双星中。在此背景下,我们报告发现NGTS-EB-7 AB系统,这是一个包含一颗晚型M矮星次星和一颗演化G型主星的食双星。次星半径为0.125 ± 0.006 R⊙,质量为0.096 ± 0.004 M⊙,并沿高偏心轨道(e = 0.71436 ± 0.00085)运行,周期为193.35875 ± 0.00034天。这使NGTS-EB-7 AB成为次星质量小于200 M_J、且质量和半径约束优于5%的食双星系统中周期第三长的系统。此外,NGTS-EB-7位于即将开展的PLATO任务拟议LOPS2南天区中心附近,从而能够探测次食并测量伴星温度。凭借其长周期和受到良好约束的物理性质,NGTS-EB-7 B将为食双星中的M矮星样本提供有价值的补充,并有助于确定晚型M矮星准确的经验质量/半径关系。

英文摘要:

Despite being the most common types of stars in the Galaxy, the physical properties of late M dwarfs are often poorly constrained. A trend of radius inflation compared to evolutionary models has been observed for earlier type M dwarfs in eclipsing binaries, possibly caused by magnetic activity. It is currently unclear whether this trend also extends to later type M dwarfs below the convective boundary. This makes the discovery of lower-mass, fully convective, M dwarfs in eclipsing binaries valuable for testing evolutionary models especially in longer-period binaries where tidal interaction between the primary and secondary is negligible. With this context, we present the discovery of the NGTS-EB-7 AB system, an eclipsing binary containing a late M dwarf secondary and an evolved G-type primary star. The secondary star has a radius of $0.125 \pm 0.006 R_\odot$ , a mass of $0.096 \pm 0.004 M_\odot$ and follows a highly eccentric $(e=0.71436 \pm 0.00085)$ orbit every $193.35875 \pm 0.00034$ days. This makes NGTS-EB-7 AB the third longest-period eclipsing binary system with a secondary smaller than $200 M_J$ with the mass and radius constrained to better than $5 \%$. In addition, NGTS-EB-7 is situated near the centre of the proposed LOPS2 southern field of the upcoming PLATO mission, allowing for detection of the secondary eclipse and measurement of the companion`s temperature. With its long-period and well-constrained physical properties - NGTS-EB-7 B will make a valuable addition to the sample of M dwarfs in eclipsing binaries and help in determining accurate empirical mass/radius relations for later M dwarf stars.

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。

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