Issues in applying the Gaia DR2 data to determine the main parameters of open star clusters and the use of a formal, two‐color diagram for the initial selection of cluster members are discussed. The possibility of using the catalog estimates of interstellar absorption is considered. It has been shown that these estimates correlate with the E(B − V) values; therefore, E(B − V) values known for many clusters can be used to obtain the interstellar absorption and color excesses in the Gaia system. Distance estimates obtained from the averaged trigonometric parallaxes of probable members are reliable up to distance of 1.5 − 2 kpc from the Sun.

中文翻译：

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有关开放集群和GAIA DR2数据的一些说明

讨论了应用Gaia DR2数据确定开放星团的主要参数以及使用正式的双色图初步选择星团成员的问题。考虑使用星际吸收的目录估计的可能性。结果表明，这些估计值与E（B  -  V）值相关。因此，许多星团已知的E（B  -  V）值可用于获得盖亚系统中的星际吸收和颜色过量。从可能的成员的平均三角视差获得的距离估计值在1.5 − 2的距离内是可靠的 太阳的KPC。