text: The same is true of several C-type asteroids studied by ground-based telescopes equipped with adaptive optics systems ( 45 Eugenia , 90 Antiope , 87 Sylvia and 121 Hermione ) .
simplified: The same is true of several C-type asteroids studied by ground-based telescopes with adaptive optics systems ( 45 Eugenia , 90 Antiope , 87 Sylvia and 121 Hermione ) .