limelight vs polar star

limelight

noun
  • Attention, notice, a starring or central role, present fame. 

  • A type of stage lighting once used in theatres and music halls, producing a bright light by the use of incandescent quicklime. 

verb
  • to illuminate with limelight 

polar star

noun
  • Synonym of pole star 

How often have the words limelight and polar star occurred in a corpus of books? (source: Google Ngram Viewer )