We employed recent Gaia/DR2 data to investigate the dynamical status of the nearby ( 300 pc ) , old ( 2.5 Gyr ) open cluster Ruprecht 147 .
We found prominent leading and trailing tails of stars along the cluster orbit , which demonstrates that Ruprecht 147 is losing stars at fast pace .
Star counts indicate the cluster has a core radius of 33.3 arcmin , and a tidal radius of 137.5 arcmin .
The cluster also possesses an extended corona , which can not be reproduced by a simple King model .
We computed the present-day cluster mass using its luminosity and mass function , and derived an estimate of 234 \pm 52 M _ { \odot } .
We also estimated the cluster original mass using available recipes extracted from N-body simulations obtaining a mass at birth of \sim 50000 \pm 6500 M _ { \odot } .
Therefore dynamical mass loss , mostly caused by tidal interaction with the Milky Way , reduced the cluster mass by about 99 % .
We then conclude that Ruprecht 147 is rapidly dissolving into the general Galactic disc .