The strong impact of massive stars on the fate of open star clusters and tidal tails

The initial condition of young open star clusters provides important information to understand how star forms. However, we carried out star-by-star N-body models using PeTar and found that if OB stars randomly form, the fate of star clusters become unpredictable. The rich kinetical data from Gaia can help to identify the tidal streams of clusters, which can better constrain the initial OB content and improve our understanding of the nature of initial mass function.