ARMADA. I. Triple Companions Detected in B-type Binaries α Del and ν Gem
ARMADA. I. Triple Companions Detected in B-type Binaries α Del and ν Gem
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DOI：
10.3847/1538-3881/abcf4e
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发表时间：
2020-12
期刊：
影响因子：
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通讯作者：
T. Gardner;J. Monnier;F. Fekel;G. Schaefer;K. Johnson;J. L. Bouquin;S. Kraus;N. Anugu;B. Setter
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文献类型：
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作者：
T. Gardner;J. Monnier;F. Fekel;G. Schaefer;K. Johnson;J. L. Bouquin;S. Kraus;N. Anugu;B. Setter
地基光学长基线干涉测量技术能够以0.10 μ s的精度测量近距离双星系统的轨道。这种精确度使得有可能探测到双星运动中由于额外的短周期伴星的引力而产生的“摆动”。我们开始了微弧秒差分天体测量（阿尔马达）调查的安排与密歇根州的红组合器（MIRC）/MIRC-X仪器在高角分辨率天文学中心（CHARA）阵列的目的是检测巨行星和恒星伴星在双星系统中绕单个恒星。我们描述了我们的调查观察，并介绍了波长校准方案，提供精度在几十微弧秒的水平<02二进制。我们测试了我们的仪器性能上一个已知的三重系统，κ Peg，并表明，我们的调查是提供一个因素的10个更好的精度比以前类似的调查。本文介绍了两个B型双星的第三分量的天体测量探测：α Del的30天伴星和ν Gem的50天伴星。我们还用田纳西州立大学的自动光谱望远镜在费尔伯恩天文台收集了α Del的径向速度数据。我们能够测量这些系统中所有三个组成部分的轨道和质量。我们发现，先前公布的内对ν Gem的径向速度轨道与我们的视觉轨道不一致。这些轨道达到的精度表明，我们的阿尔马达调查将成功地发现新的紧凑的三重系统A/B型二进制系统，导致更好的统计分层系统架构和形成历史。
Ground-based optical long-baseline interferometry has the power to measure the orbits of close binary systems at ∼10 μas precision. This precision makes it possible to detect “wobbles” in the binary motion due to the gravitational pull from additional short-period companions. We started the ARrangement for Micro-Arcsecond Differential Astrometry (ARMADA) survey with the Michigan Infra-Red Combiner (MIRC)/MIRC-X instrument at the Center for High Angular Resoloution Astronomy (CHARA) array for the purpose of detecting giant planets and stellar companions orbiting individual stars in binary systems. We describe our observations for the survey, and introduce the wavelength calibration scheme that delivers precision at the tens of microarcseconds level for <02 binaries. We test our instrument performance on a known triple system, κ Peg, and show that our survey is delivering a factor of 10 better precision than previous similar surveys. We present astrometric detections of tertiary components to two B-type binaries: a 30 day companion to α Del, and a 50 day companion to ν Gem. We also collected radial velocity data for α Del with the Tennessee State University Automated Spectroscopic Telescope at Fairborn Observatory. We are able to measure the orbits and masses of all three components in these systems. We find that the previously published radial velocity orbit for the inner pair of ν Gem is not consistent with our visual orbit. The precision achieved for these orbits suggests that our ARMADA survey will be successful at discovering new compact triple systems to A/B-type binary systems, leading to better statistics of hierarchical system architectures and formation history.