Complex sentence: Hansen then gained attention when she appeared in a 1997 issue of "Perfect 10" magazine, when she came in second behind Ashley Degenford in "Perfect 10" magazine's first annual model search.
Split into simpler sentences: Hansen then gained attention when she appeared in a 1997 issue of "Perfect 10" magazine. She came in second behind Ashley Degenford in "Perfect 10" magazine's first annual model search.