The authors present V-band photometry of the long-period RS CVn-type binary λ Andromedae (P(phot.) = 53.952 days) carried out in the observing seasons 1981 - 82 and 1982 - 83. They covered one complete cycle in 1981 - 82 and more than three contiguous cycles in 1982 - 83. Maximum amplitudes (full range) are about 0<SUP>m</SUP>.22 and 0<SUP>m</SUP>.19, respectively. An analysis of the existing epochs of maximum and minimum light confirms the photometric period given by Boyd et al. (1983) but discloses the existence of a quasi-periodic trend in the (O-C) curve suggesting cyclic changes on a time scale of about 9 years. The fourier analysis of the 1982 - 83 record shows a certain spread in frequency around the fundamental periodicity; this can be interpreted as due to the presence of dark spots highly spread in latitude, moving at different velocities owing to the differential rotation of the star.
Photometric changes and SPOT motion in Lambda Andromedae
BUSSO, Maurizio Maria;
1984
Abstract
The authors present V-band photometry of the long-period RS CVn-type binary λ Andromedae (P(phot.) = 53.952 days) carried out in the observing seasons 1981 - 82 and 1982 - 83. They covered one complete cycle in 1981 - 82 and more than three contiguous cycles in 1982 - 83. Maximum amplitudes (full range) are about 0m.22 and 0m.19, respectively. An analysis of the existing epochs of maximum and minimum light confirms the photometric period given by Boyd et al. (1983) but discloses the existence of a quasi-periodic trend in the (O-C) curve suggesting cyclic changes on a time scale of about 9 years. The fourier analysis of the 1982 - 83 record shows a certain spread in frequency around the fundamental periodicity; this can be interpreted as due to the presence of dark spots highly spread in latitude, moving at different velocities owing to the differential rotation of the star.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
