The motions of G1, G2, G3, KPNO 15, and HP Tau are shown in this figure in the time interval from 5600 to 3150 yr ago in steps of 350 yr. The nominal time of breakup for the G2/KPNO 15 pair is 5606 yr and 4869 yr for G1/G3. Note that the position and proper motion of G3 are affected by its close (31 mas) companion. The K4 star HP Tau is slowly crossing the stellar group and possibly disturbing it.