标题： 具有 Hipparcos I 的疏散星团。 平均天文参数 显示英文标题

标题： Open clusters with Hipparcos I. Mean astrometric parameters

摘要： 利用依巴谷数据计算了所有距离小于 300 pc 的 9 个疏散星团（不包括昂宿星团）和 9 个富星团（距离在 300 至 500 pc 之间）的新成员、平均视差和自行。 视差的精度范围为 0.2 到 0.5 毫角秒，自行的精度范围为 0.1 到 0.5 毫角秒/年，这对于校准光度视差以及运动学研究具有重要意义。 对可能的偏差进行了仔细调查，未发现平均星团视差存在显著系统误差的证据。 还给出了 32 个更远星团的距离和自行，这些星团可以用于统计分析。 显示英文摘要

摘要： New memberships, mean parallaxes and proper motions of all 9 open clusters closer than 300 pc (except the Hyades) and 9 rich clusters between 300 and 500 pc have been computed using Hipparcos data. Precisions, ranging from 0.2 to 0.5 mas for parallaxes and 0.1 to 0.5 mas/yr for proper motions, are of great interest for calibrating photometric parallaxes as well as for kinematical studies. Careful investigations of possible biases have been performed and no evidence of significant systematic errors on the mean cluster parallaxes has been found. The distances and proper motions of 32 more distant clusters, which may be used statistically, are also indicated.