projected rotational velocity
tondâ-ye carxeši-ye farâšândé
Fr.: vitesse rotationnelle projetée
The → angular velocity of a star deduced from the → rotational broadening of its → spectral lines. It is expressed as v sini, where i is the → inclination of the rotational axis with respect to the normal to the → plane of the sky. The real equatorial rotational velocity can be determined only if the inclination of the rotational axis is known.