open cluster的用法和樣例：
例句
- The Pleiades nebulosity is caused by a chance encounter between an open cluster of stars and a molecular cloud.
昴星團是在一次偶然的機會(huì )下，由一個(gè)疏散星團與一個(gè)分子星云遭遇而形成的。 - In this scenario, the cluster stars drift off as other stars in the galaxy gravitationally tug on them.
在星系其他恒星的重力吸引下，疏散星團會(huì )逐漸散開(kāi)，被其他恒星吞噬。
