M4 is one of the most open, or loosely constructed of globular clusters, as its high-classification of IX indicates (the higher the number, the less dense the cluster). Its central mass measures about 8 light years in diameter, but its full reach is 75 light years across. On top of that, its gravitational influence stretches for about 140 light years.
Create an account to join the discussion
Create AccountI'm a software developer and beginner Astrographer based in the UK. I built the core features of Astrographer for myself as I was learning the hobby and thought they might be useful to others!