شعاع ِ همچرخش
Fr.: rayon de corotation
1) In the → X-wind model of → accretion,
the distance from the star where the → centrifugal force
on a particle corotating with the star balances the
→ gravitational attraction; in other words, where the
→ accretion disk rotates at the same
→ angular velocity as the star.
2) In a → spiral galaxy,
the place where the spiral → pattern speed
has the same velocity as the → rotation curve of the
→ galactic disk.
In the frame rotating with the wave, particles inside this radius will appear to
revolve in the direction of the frame rotation (prograde) while outside this corotation
radius, they will be retrograde.
→ corotation; → radius.