按运动学方法确定疏散星团M11的距离

DETERMINING THE DISTANCE OF OPEN CLUSTER M11 FROM THE PURE KINEMATICAL OBSERVATIONAL DATA

在合理假设星团成员星的内部随机运动为各向同性的基础上,提出一种利用纯运动学资料确定星团距离的方法,并依此方法估算出疏散星团M11的速度距离为(1．89±0．52)kpc。这一结果与其他作者给出的星团M11的光度距离符合得相当好。

On the basis of reasonable supposing that the internal random motions of member stars in a cluster are of isotropic distribution, an approach to determine the distances of open star clusters from pure kinematical observational data including line-of-sight velocities and proper motions is developed, which is an absolute distance measurement technique and completely independent of the luminosity distance of clusters obtained from the relative distance measurement. Using this approach, the velocity distance of the open cluster M11 is determined to be （ 1.89±0. 52） kpc, which is in good agreement with the luminosity distances of the cluster derived from different authors. Some problems concerned are also discussed briefly.