标题： 宽双星的偏心率分布 显示英文标题

标题： Eccentricity distribution of wide binaries

摘要： 利用一种新的统计方法，研究了距离67秒差距以内、投影分离大于50天文单位的477个太阳型双星样本。 相对运动的速度和方向由短弧观测数据或已知轨道确定，并将其联合分布与数值模拟结果进行比较。 通过借助模拟反演观测分布，我们发现宽双星的平均偏心率为 0.59±0.02，偏心率分布可以建模为 f(e) ≈ 1.2e + 0.4。 然而，包含内子系统的宽双星（即三重或多重复合系统）具有显著较小的偏心率，平均值 e = 0.52±0.05，峰值出现在 e ≈ 0.5。 我们发现视觉轨道目录对大偏心率存在强烈偏差。 对于此样本，发现了偏心率随分离距离（或周期）增加的边缘证据。 与光谱双星的对比证明了有争议的周期-偏心率关系的真实性。 平均偏心率确实随着双星周期增加，从 10^2 到 10^3 天的双星平均偏心率为 0.39，而我们研究的双星（10^5 到 10^6 天）平均偏心率为 0.59。 显示英文摘要

摘要： A sample of 477 solar-type binaries within 67pc with projected separations larger than 50AU is studied by a new statistical method. Speed and direction of the relative motion are determined from the short observed arcs or known orbits, and their joint distribution is compared to the numerical simulations. By inverting the observed distribution with the help of simulations, we find that average eccentricity of wide binaries is 0.59+-0.02 and the eccentricity distribution can be modeled as f(e) ~= 1.2 e + 0.4. However, wide binaries containing inner subsystems, i.e. triple or higher-order multiples, have significantly smaller eccentricities with the average e = 0.52+-0.05 and the peak at e ~ 0.5. We find that the catalog of visual orbits is strongly biased against large eccentricities. A marginal evidence of eccentricity increasing with separation (or period) is found for this sample. Comparison with spectroscopic binaries proves the reality of the controversial period-eccentricity relation. The average eccentricity does increase with binary period, being 0.39 for periods from 10^2 to 10^3 days and 0.59 for the binaries studied here (10^5 to 10^6 days).