Nemesis by Isaac Asimov Fred Major

One of the colonies, Rotor, has broken away from the solar system to create its own renegade utopia around an unknown red star two light-years from a star named Nemesis. Now a fifteen-year-old Rotorian girl has learned of the dire threat that nemesis poses to Earth's people—but she is prevented from warning them. a girl and boy in the midst of a government conspiracy in the tiny, isolated town of Fire Lake in Idaho. Min has been murdered on her even numbered birthdays ever since she was eight.