cynosure vs most prominent element

cynosure

noun
  • Ursa Minor or Polaris, the North Star, used as a guide by navigators. 

  • That which serves to guide or direct; a guiding star. 

  • Something that is the center of attention; an object that serves as a focal point of attraction and admiration. 

most prominent element

How often have the words cynosure and most prominent element occurred in a corpus of books? (source: Google Ngram Viewer )