We have calculated proper motions and re-evaluated the membershipprobabilities of 810 stars in the area of two NGC objects, NGC 1817 and NGC1807. We have obtained absolute proper motions from 25 plates in the referencesystem of the Tycho-2 Catalogue. The plates have a maximum epoch difference of81 years; and they were taken with the double astrograph at Zo-Se station ofShanghai Observatory, which has an aperture of 40 cm and a plate scale of 30arcsec/mm. The average proper motion precision is 1.55 mas/yr. These propermotions are used to determine the membership probabilities of stars in theregion, based on there being only one very extended physical cluster: NGC 1817.With that aim, we have applied and compared parametric and non-parametricapproaches to cluster/field segregation. We have obtained a list of 169probable member stars.
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机译：我们已经计算出适当的运动，并重新评估了两个NGC天体NGC 1817和NGC1807区域中810星的隶属度。我们从Tycho-2目录的参考系统中的25个板上获得了绝对正确的运动。印版的最大历时差为81年；这些照片是在上海天文台Zo-Se站用双天文相机拍摄的，它的孔径为40 cm，板刻度为30arcsec / mm。平均适当运动精度为1.55 mas / yr。基于只有一个非常扩展的物理星团：NGC 1817，这些固有运动被用来确定该地区恒星的隶属概率。为此，我们将参数和非参数方法应用于星团/场隔离。我们已经获得了169个可能的成员恒星的列表。
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