论文标题
二进制及以后的一颗星际I.调查描述和VLTI/重力观察的首先结果，对具有高gaia-hipparcos加速度的巨大靶标观测
Binarity and beyond in A stars I. Survey description and first results of VLTI/GRAVITY observations of VAST targets with high Gaia-Hipparcos accelerations
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WDS的连接尚不清楚，并且两种多重性的观察映射远非完整。探索了数十亿个AU的可能同伴。我们正在进行一项近红外干涉测量调查，vlti/重力在广阔的样品中的108 A Southern A恒星中有二十个，显示了较大的Gaia-Hipparcos适当的运动变化，表明$ 1-20 $ AU的分离为$ M \ sim 1 m _ {\ odot} $伴随。在本文中，我们详细介绍了样本选择，并报告了$ 8 _ { - 0}^{+2} $新星（包括四个高多样性（3+）系统）的干涉测量检测，该目标是在13个目标的部分样本中。此外，我们还使用Gaia EDR3进行了共同的适当运动搜索，对108 A颗星进行了搜索，这导致了10个新的检测，并确认了几个以前的自适应光学伴侣。我们在恒星的分离分布的背景下讨论了我们的初步结果及其对WDS多样性的影响。特别是，我们发现（i）明显抑制了低于30-50 au的恒星的同伴很可能是由于观察性偏见而导致的，（ii）这一事实是，在6个最接近的wds中，有4个伴侣在几十u au中具有统计流感是一种统计流感，但是10-20个这样的二线可能仍然很可能在20 pc（III中）（iii）（iii）（iii）（iii）（iii）（iii）（iii）（iii）（iii）（iii），（iii yii）（iii）（iii for）（iii for），（iii）很可能会出现。 （$ <1 $ au）主要A星的同伴，因此必须经历非平凡的进化。
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 the observational mapping of both multiplicities are far from complete. Possible companions at separations of tens of AU are particularly poorly explored. We are conducting a near-infrared interferometric survey with VLTI/GRAVITY of twenty out of 108 southern A stars within the VAST sample which show large Gaia-Hipparcos proper motion changes suggestive of a $M \sim 1 M_{\odot}$ companion at separations of $1-20$ AU. In this paper, we detail our sample selection and report on the interferometric detection of $8_{-0}^{+2}$ new stars (including four high multiplicity (3+) systems) in a partial sample of 13 targets. Moreover, we also conduct a common proper motion search for the 108 A stars using Gaia eDR3 and which resulted in 10 new detections and confirmation of several previous Adaptive Optics companions as physical. We discuss our preliminary results in the context of the separation distribution of A stars and implications for the multiplicity of WDs. In particular, we find that (i) the apparent suppression of companions to A stars below about 30-50 AU is very likely due to an observational bias, (ii) the fact that 4 of the 6 closest WDs have a companion within a few tens of AU is a statistical fluke but 10-20 such binaries are likely still missing within 20 pc, (iii) a large fraction of such systems likely had high multiplicity (3+) progenitors with very close ($< 1$ AU) companions to the primary A star, and must therefore have undergone non-trivial evolution.
