Sidereal

Sidereal, of the stars, may refer to:

• Measurements of time:
  • Sidereal time
  • Sidereal day
  • Sidereal month
  • Sidereal year
• Sidereal period of an object orbiting a star
• Sidereal astrology
• Sidereus Nuncius, or Sidereal Messenger, a scientific work by Galileo Galilei