论文标题
超越星星II中的二进制。在三重髋关节87813附近拆开四颗星HJ2814
Beyond binarity in A stars II. Disentangling the four stars in the vicinity of the triple HIP 87813 within the quintuple system HJ2814
论文作者
论文摘要
A-Star是当前存在的大约一半的白矮人（WDS）的祖细胞。 A-Star的多重性与WD的多重性之间的联系尚不清楚，并且两个多重性仍然很差。我们正在对108个南部A型星的样本进行严格的约束，这些恒星是附近庞大的样本\ citep {derosa14}的一部分，通过对（其中有二十个）恒星进行近红外的干涉测量观察，其中具有$ GAIA $ -GAIA $ -YPIPPARCOS $加速。在本文中，我们结合了光谱，自适应光学成像，NIR干涉法和$ GAIA $ - $ HIPPARCOS $ ASTROMETRY，以便在复杂的HIP 87813 = HJ2814A系统中删除星星。我们表明（i）（i）先前发现的微弱恒星，与A星相隔2英寸实际上是一个背景来源；（ii）$ Gaia $ - $ - $ - $ - hipparcos $加速是由新发现的新发现的$ 0.74 m _ {\ odot} $ star在先前的ao图像中所遗漏的，我们以前是$ p \ ober texters \ bit;我们表明，在13.4天的轨道上，A恒星在13.4天的轨道上具有非常接近的$ 0.85 m _ {\ odot} $。并将在哈勃时间左右内导致2至5个绑定的WD的系统。
A-stars are the progenitors of about half of the white dwarfs (WDs) that currently exist. The connection between the multiplicity of A-stars and that of WDs is not known and both multiplicities are still poorly explored. We are in the process of obtaining tight constraints on a sample of 108 southern A-type stars that are part of the nearby VAST sample \citep{DeRosa14} by conducting near-infrared interferometric follow-up observations to the (twenty) stars among them which have large $Gaia$-$Hipparcos$ accelerations. In this paper, we combine spectroscopy, adaptive optics imaging, NIR interferometry and $Gaia$-$Hipparcos$ astrometry in order to disentangle the stars in the complicated HIP 87813 = HJ2814A system. We show that (i) a previously discovered faint star that is separated by 2" from the A star is actually a background source; (ii) the $Gaia$-$Hipparcos$ acceleration is caused by a newly discovered $0.74 M_{\odot}$ star that was missed in previous AO images and we solve for its $P \approx 60 \text{ yrs}$ astrometric orbit; (iii) by combining previously obtained spectra we show that the A star has a very close $0.85 M_{\odot}$ companion on a 13.4-day period orbit. The radial velocity curve combined with NIR interferometry constrains its orbit allowing Kozai-Lidov oscillations in the hierarchical triple to be ruled out. The system HJ2814 is one of only about fifteen known 5+ systems with an A star primary, and will result in a system of between two to five bound WDs within around a Hubble time.
