White Dwarfs in Open Clusters

bolte, Michael j . .这个项目的研究人员正在对年轻的疏散星团中的白矮星进行广泛的搜索，其主要目标是确定主序恒星质量，在主序恒星质量之上的恒星爆炸为核心坍缩超新星，在主序恒星质量之下的恒星以白矮星的形式结束生命。这个临界质量的价值在很多领域都很重要。恒星群中核心坍缩超新星的数量对星系中的化学富集和能量平衡具有重要意义。超新星动能反馈可能是矮星系早期演化的主导过程，是调节各质量年轻星系恒星形成的重要机制。目前临界质量值的不确定性很大，在最近的文献中，临界质量的值在5到8个太阳质量之间。确定白矮星形成的临界质量对于提供巨星物理过程的约束也很重要，这些物理过程导致核心的形成和成长，最终成为白矮星的残骸。该方案的一个有价值的附带好处是改进了对许多年轻和中年开放星团的年龄、距离和初始质量函数的估计。更广泛的影响。在研究过程中，研究人员将他们的数据和分析工具免费发布在一个WWW网站上。天文学和物理学的研究生和本科生都参与了这项研究。

AST 0307492Bolte, Michael J.The investigators in this project are carrying out an extensive search for white dwarf stars in young open clusters with the primary goal to identify the main sequence stellar mass above which stars explode as core collapse supernovae and below which stars end their lives as white dwarfs. The value for this critical mass is important in a wide range of areas. The number of core-collapse supernovae in a stellar population has important implications for chemical enrichment and energy balance in galaxies. Supernovae kinetic energy feedback may be the dominant process in the early evolution of dwarf galaxies and is an important mechanism for regulating star formation in young galaxies of all masses. The current uncertainty in the value of the critical mass is large with values in the recent literature ranging from 5 to 8 solar masses. Identifying the critical mass for the formation of white dwarfs is also important for providing constraints on physical processes in giant stars that lead to the formation and growth of the core that eventually becomes thewhite dwarf remnant. A valuable side benefit of this program is improved estimates of the ages, distances and initial mass functions of a number of young and intermediate-age open clusters. Broader Impact. The researchers are making their data and analysis tools available freely at a WWW site during the course of the work. Astronomy and physics graduate and undergraduate students are involved in the research.