= [?] { \ displaystyle { \ begin { bmatrix } x _ { ecliptic } \ \ y _ { ecliptic } \ \ z _ { ecliptic } \ \ \ end { bmatrix } } = { \ begin { bmatrix } 1 & 0 & 0 \ \ 0 & \ cos \ epsilon & \ sin \ epsilon \ \ 0 &  @-@  \ sin \ epsilon & \ cos \ epsilon \ \ \ end { bmatrix } } \ ! \ cdot \ ! { \ begin { bmatrix } x _ { equatorial } \ \ y _ { equatorial } \ \ z _ { equatorial } \ \ \ end { bmatrix } } }.
