We present the photometric properties of V608 Cas from detailed studies of light curves and eclipse timings. The light curve synthesis indicates that the eclipsing pair is an overcontact binary with parameters of ΔT = 155 K, q = 0.328, and f = 26%. We detected the third light ℓ3, which corresponds to about 8% and 5% of the total systemic light in V and R bands, respectively. Including our 6 timing measurements, a total of 38 times of minimum light were used for a period study. It was found that the orbital period of V608 Cas has varied in some combination of an upward parabola and two periodic variations. The continuous period increase with a rate of +3.99 × 10−7 d yr−1 can be interpreted as a mass transfer from the secondary component to the primary star at a rate of 1.51 × 10−7 M⊙ yr−1. The periods and semi-amplitudes of the two periodic variations are about P3 = 16.0 yr and P4 = 26.3 yr, and K3 = 0.0341 d and K4 = 0.0305 d, respectively. The most likely explanation of both cycles is a pair of light-traveling time effects operated by the possible presence of third and fourth components with estimated masses of M3 = 2.20 M⊙ and M4 = 1.27 M⊙ in eccentric orbits of e3 = 0.66 and e4 = 0.52. Because the contribution of ℓ3 is very low compared to the estimated masses of two circumbinary objects, they can be inferred as very faint compact objects.

We present an analysis of the measurements of mid-eclipse times of V839 Oph, collected from literature sources. Our analysis indicates a period increase of 3.2 X 10-7 day/yr. This period increase of V839 Oph can be interpreted in terms of mass transfer of rate 1.76 X 10-7⊙/yr, from the less to the more massive component. The O - C diagram shows a damping sine wave covering two different complete cycles of 36.73 yr and 19.93 yr with amplitudes approximately equal to 0.0080 and 0.0043 day, respectively. The third cycle has to be expected to cover about 13.5 years with lower amplitude than those of the former two cycles. These unequal duration cycles show a non periodicity which may be explained as resulting from either the presence of a tertiary component to the system or cyclic magnetic activity variations due to star spots. For the later mechanism, the obtained characteristics are consistent when applying Applegate (1992) mechanism.