Challenge 1: Single mass clusters, isolated and tidally limited.

Challenge 2: Multi-mass clusters, no stellar evolution

Challenge 3: Clusters in tidal fields with stellar evolution

Challenge 4: Comparison of mass modelling methods using N-body model of M4.

The definition of the stellar types (KSTAR) used in the NBODY6 snapshots can be found in the Appendix.

There 23 possible stellar types (KSTAR) in NBODY

     0       Low main sequence (M < 0.7).
     1       Main sequence.
     2       Hertzsprung gap (HG).
     3       Red giant.
     4       Core Helium burning.
     5       First AGB.
     6       Second AGB.
     7       Helium main sequence.
     8       Helium HG.
     9       Helium GB.
    10       Helium white dwarf.
    11       Carbon-Oxygen white dwarf.
    12       Oxygen-Neon white dwarf.
    13       Neutron star.
    14       Black hole.
    15       Massless supernova remnant.
    19       Circularizing binary (c.m. value).
    20       Circularized binary.
    21       First Roche stage (inactive).
    22       Second Roche stage.