论文标题
在亨利·德雷珀（Henry Draper One）的二进制轨道上（HD 1）
On the binary orbit of Henry Draper one (HD 1)
论文作者
论文摘要
我们介绍了晚期型光谱二进制HD 1。使用的最终轨道是使用机器人Stella设施及其高分辨率Echelle Sphelle Speprograph SES的13年观察结果的553个光谱。它的长期径向速度稳定性为$ \ $ 5000万美元。 HD 1的单个径向速度达到63m/s的RMS残差，接近预期的精度。 HD 1的光谱线在旋转上宽扩大，$ v \ sin i $ $ $ \ pm $ \ $ 0.1 km/s。整个光谱似乎是单线的，并产生了一个偏心率为0.5056 $ \ pm $ 0.0005的轨道，半振幅为4.44 km/s。我们仅根据SES数据来限制和完善轨道周期，至2318.70 $ \ pm $ 0.32D，而2317.8 $ \ pm $ \ pm $ 1.1D包括DAO和Cambridge/Coravel发布的较旧数据集。由于SES数据的较高精度，我们仅基于轨道计算，仅在Stella/SES速度上，以免降解其溶液。我们从光谱合成中重新确定了HD 1的天体物理参数，并与新的{\ it Gaia} dr-2视差一起提出了比以前发布的更高的光度。我们得出的结论是，HD 1是一款略有金属缺陷的K0 III-II巨头，比太阳高217倍。次级在光学波长处保持看不见。我们提供了存在第三个成分的证据。
We present our final orbit for the late-type spectroscopic binary HD 1. Employed are 553 spectra from 13 years of observations with our robotic STELLA facility and its high-resolution echelle spectrograph SES. Its long-term radial-velocity stability is $\approx$50m/s . A single radial velocity of HD 1 reached a rms residual of 63m/s, close to the expected precision. Spectral lines of HD 1 are rotationally broadened with $v\sin i$ of 9.1$\pm$0.1 km/s . The overall spectrum appears single-lined and yielded an orbit with an eccentricity of 0.5056$\pm$0.0005 and a semi-amplitude of 4.44km/s . We constrain and refine the orbital period based on the SES data alone to 2318.70$\pm$0.32d, compared to 2317.8$\pm$1.1d when including the older data set published by DAO and Cambridge/Coravel. Owing to the higher precision of the SES data, we base the orbit calculation only on the STELLA/SES velocities in order not to degrade its solution. We redetermine astrophysical parameters for HD 1 from spectrum synthesis and, together with the new {\it Gaia} DR-2 parallax, suggest a higher luminosity than published previously. We conclude that HD 1 is a slightly metal-deficient K0 III-II giant 217 times more luminous than the Sun. The secondary remains invisible at optical wavelengths. We present evidence for the existence of a third component.
