Rotating variables

In a sense, all stars rotate, though the speed at which they do so may be very close to zero. If they do rotate, it only becomes clear if there is some feature that varies in longitude and therefore causes brightness variations as the star rotates. Many such classes exist; the few described here either have magnetic spots (BY Draconis variables), chemical spots (α² Canum Venaticorum variables), or non-axisymmetric distortions from the gravity of a close companion (ellipsoidal variables).

• BY Draconis variables
  • BY Draconis
• α² Canum Venaticorum variables
  • α² Canum Venaticorum
  • ε Ursa Majoris
  • α Doradus
  • α Piscium
  • β Hydrae
• Ellipsoidal variables
  • π Cassiopeiae