Original: Asterisms Big Dipper or Plough The seven brightest stars of Ursa Major form the well-known asterism known as the Big Dipper in the United States and Canada , or the Plough in the United Kingdom and Ireland .
Simplified: The Big Dipper The seven stars in the upper-left corner of Ursa Major form an asterism called the Big Dipper ( or the Plough in Great Britain ) .