A trio of horseshoes: past, present and future dynamical evolution of Earth co-orbital asteroids 2015 XX 169 $\mbox{XX}_{169}$ , 2015 YA and 2015 YQ 1 $\mbox{YQ}_{1}$

A trio of horseshoes: past, present and future dynamical evolution of Earth co-orbital asteroids 2015 XX 169 $\mbox{XX}_{169}$ , 2015 YA and 2015 YQ 1 $\mbox{YQ}_{1}$