code: def sidereal_time(t):
      
  
      # Compute the Earth Rotation Angle.  Time argument is UT1.
  
      theta = earth_rotation_angle(t.ut1)
  
      # The equinox method.  See Circular 179, Section 2.6.2.
      # Precession-in-RA terms in mean sidereal time taken from third
      # reference, eq. (42), with coefficients in arcseconds.
  
      t = (t.tdb - T0) / 36525.0
      st =        ( 0.014506 +
          (((( -    0.0000000368   * t
               -    0.000029956  ) * t
               -    0.00000044   ) * t
               +    1.3915817    ) * t
               + 4612.156534     ) * t)
  
      # Form the Greenwich sidereal time.
  
      return (st / 54000.0 + theta * 24.0) % 24.0
docs: Compute Greenwich sidereal time at the given ``Time``.