関連ワード:  stephenson 2-18 largest star    stephenson 2 18 largest star in the universe    is stephenson 2 18 the biggest star in the universe    is stephenson 2 18 the biggest star or uy scuti    is stephenson 2 18 the biggest star in the milky way    is stephenson 2 18 the biggest star in the world    when did stephenson 2 18 become the largest star    is stephenson 2 18 the largest known star    largest star than stephenson 2 18    star bigger than stephenson 2-18