Title: Catching a Milky Way open cluster in its last breath Show Chinese title

Title: 捕捉银河系疏散星团的最后一口气

Abstract: Theoretical models have suggested peculiar velocity dispersion profiles of star clusters facing dissolution. They predicted that, besides bound stars that still belong to the star cluster, and unbound ones already stripped off, there is an intermediate population of stars that having acquired the enough energy to escape the cluster are still within the cluster Jacobi radius. Both, potential escapers and unbound stars, show hot kinematics, not observed along tidal tails of star clusters. We report on the first evidence of an open cluster with stars crossing such a transitional scenario, namely: ASCC 92. The open cluster gathers nearly 10 percent of its initial total mass, and is moving toward Galactic regions affected by higher interstellar absorption. Precisely, the obscured appearance of the cluster could have hampered disentangling its true internal dynamical evolutionary stage, previously. Show Chinese abstract

Abstract: 理论模型已经提出了星团面对瓦解时特有的速度弥散分布情况。 它们预测，除了仍然属于星团的束缚恒星和已经被剥离的非束缚恒星外，还存在一个中间恒星群体，这些恒星已经获得了足够的能量以逃逸出星团，但仍位于星团的雅可比半径内。 潜在的逃逸恒星和非束缚恒星都表现出高温动力学特性，在星团的潮汐尾部并未观察到这种现象。 我们报告了第一个具有跨越这种过渡情景的疏散星团的证据，即：ASCC 92。 这个疏散星团聚集了其初始总质量的近10%，并且正向银河系中受到更高星际吸收影响的区域移动。 确切地说，该星团被遮挡的外观可能之前妨碍了对其真实内部动力学演化阶段的区分。