摘要：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 ≈ 84°), 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.
关键词：binaries: eclipsing;binaries: visual;stars: fundamental parameters;stars: individual: V994 Her
