2011A&A...536A..64E

Using recent observational data we present N-body simulations of the Hyades open cluster. We make an attempt to determine the initial conditions of the Hyades cluster at the time of its formation to reproduce the present-day cumulative mass profile, stellar mass and luminosity function (LF). We performed direct N-body simulations of the Hyades in an analytic Milky Way potential. They account for stellar evolution and include primordial binaries in a few models. Furthermore, we applied a Kroupa initial mass function and used extensive ensemble-averaging. We find that evolved single-star King initial models with King parameters W₀=6-9 and initial particle numbers N₀=3000 provide good fits to the present-day observational cumulative mass profile within the Jacobi radius. The best-fit King model has an initial mass of 1721M_☉ and an average mass loss rate of -2.2M_☉/Myr. The K-band LFs of models and observations show reasonable agreement. Mass segregation is detected in both observations and models. If 33% primordial binaries are included, the initial particle number is reduced by 5% as compared to the model without primordial binaries. The present-day properties of the Hyades can be reproduced well by a standard King or Plummer initial model when choosing appropriate initial conditions. The degeneracy of good-fitting models can be quite high due to the large dimension of the parameter space. More simulations with different Roche-lobe filling factors and primordial binary fractions are required to explore this degeneracy in more detail.