演講資訊

摘要：

Blue straggler stars are rejuvenated core hydrogen-burning stars that are bluer and brighter than the main sequence turnoff stars of a cluster. They are prevalent in all stellar environments due to their diverse formation mechanisms, such as binary evolution and multiple stellar interactions. Observational pieces of evidence indicate that these objects are the most massive among the cluster populations. Due to this, these objects provide insights into the interplay between the internal dynamics and stellar evolution of their host systems. Star clusters are collisional systems in which stellar dynamics cause massive objects to sink faster into the cluster core. Being the most massive objects, blue straggler stars strictly abide by this trait. Such an observational signature is not only an important tool to assess the dynamical status of the cluster but can also provide clues to the formation mechanisms of these objects. We estimate the relative sedimentation level of the blue straggler star population of 23 old open clusters (ages > 1 Gyr) for the first time in the literature, utilising various methods such as blue straggler stars' radial distributions and estimating the area enclosed between cumulative radial distributions of blue straggler stars and other reference populations. Finally, we date the dynamical ages of open clusters by comparing empirical and theoretical parameters.