Polaris is a mutant possessing the power to control magnetism, including manipulating metals which are susceptible to that force. She can also manipulate the Earth's magnetic field to allow herself to fly. She has bright green hair, another indication of her mutation.
History
Polaris was first encountered by the X-Men when Magneto convinced her that she was his daughter and used her in his effort to establish the supremacy of mutants over normal humanity. This gambit was revealed and Polaris learned the error of her ways, joining the X-Men for a time. For a while her teammate Iceman had a crush on her, but Polaris didn't truly reciprocate the feeling.
She did, however, fall in love with her teammate Havok, and the two left the X-Men, returning from time to time to assist the team.
The pair eventually joined an incarnation of X-Factor as its leaders.