Updated study of the quintuple system V994 Herculis

Abstract

Aims: We present a new updated study of the unique quintuple system of two eclipsing binaries, V994 Her. Methods: Based on new obtained photometric observations, we analysed the period variations of the two eclipsing pairs of V994 Her. Results: We found that the orbital period of the two eclipsing binaries around a common barycenter is about 2.9 yrs instead of the original period, which was reported as 6.3 yrs. Moreover, the system now seems to be close to coplanar (i ~ 84deg), and we also revised the individual masses of all four eclipsing components. The two eclipsing pairs show slow apsidal motion with periods of about 116 and 111 yrs, respectively. Pairs A and B are distant by about 17 mas on the sky, which is encouraging for observers because an interferometric detection may be possible in the next years. Conclusions: All of these results are based on the photometric observations of V994 Her and its detailed analysis of the period changes of the two eclipsing binaries.