Research Information System
ASTRONOMICAL JOURNAL, vol.101, no.1, pp.201-207, 1991 (SCI-Expanded)
All available times of minima of AH Virginis have been compiled and analyzed for the period variation in the system. Two major abrupt changes (DELTA-P/P) of 8.7 x 10(-6) and 1.4 X 10(-5) were found to have occurred in 1955 and 1971, respectively. Fluctuations in certain time intervals of the period around mean values were also noted. Mass transfers of about 3 X 10(-6) and 5 X 10(-5) M. from the less massive component are required to account for two observed abrupt period increases. Fluctuations of the period with the period of about 10 yr and amplitude of 0.02 day are discussed in terms of (i) the light-time effect due to a third body in the system, (ii) magnetically induced deformations in the convective layer, and (iii) mass motions in the radiative core of a component star. It is shown that the hypothetical third body cannot be ADS 8472B, and its mass could not be less than about 0.5 M.. No clear correlation is found between the period and asymmetry changes. If the asymmetry is a measure of magnetic activity, it is hard to argue that the alternating period changes are due to magnetically induced deformations in the convective layer of a component of AH Vir.