Dm. Pyper et al., AN ABRUPT DECREASE IN THE ROTATIONAL PERIOD OF THE CHEMICALLY PECULIAR MAGNETIC STAR CU VIRGINIS, Astronomy and astrophysics (Berlin), 339(3), 1998, pp. 822-830
Spectroscopic and photometric observations of the chemically peculiar
star CU Vir over 40 years show that the period of variations decreased
by 0.005 % between 1983-1987. The assumption of the rigid rotator mod
el for this star implies an abrupt change of the rotation rate. We fin
d no spectroscopic evidence that the star is a close binary, ruling ou
t a possibility that the period decrease is caused by the mass exchang
e.