CREATE TABLE table_45497 ("Companion  ( in order from star ) " TEXT, "Mass" TEXT, "Semimajor axis  (  AU  ) " TEXT, "Orbital period  (  s day  ) " TEXT, "Eccentricity" TEXT, "Inclination" TEXT)

What is the eccentricity when the semimajor axis is 20 au?
SELECT "Eccentricity" FROM table_45497 WHERE "Semimajor axis ( AU )" = '20 au'
SELECT "Eccentricity" FROM "table_45497" WHERE "Semimajor axis ( AU )" = '20 au'