2020MNRAS.492.4959J

We investigate the possibility that the Sun could have been born in M67 by carrying out N-body simulations of M67-like clusters in a time-varying Galactic environment, and following the Galactic orbits of stars that escape from them. We find that model clusters that occupy similar orbits to M67 today can be divided up into three groups, which we call hot, depleted, and scattered clusters. Hot clusters are born with a high initial z-velocity; depleted clusters are born on dynamically cold orbits but are destroyed by GMC encounters in the Galactic disc; and scattered clusters are born on dynamically cold orbits and survive to have more than 1000 stars at an age of 4.6 Gyr. We find that all cluster models in all three cluster groups have stellar escapers that are kinematically similar to the Sun. Hot clusters have the lowest fraction of escapers with solar-like kinematics, f☉ = 0.06 per cent, whilst depleted clusters have the highest fraction, f☉ = 6.61 per cent. We calculate that clusters that are destroyed in the Galactic disc have a specific frequency of escapers that end up on solar-like orbits that is ∼ 2 times that of escapers from clusters that survive their journey.