Updated study of the quintuple system V994 Herculis

TL;DR

This study provides an updated analysis of the V994 Herculis quintuple system, revealing a shorter orbital period, near coplanarity, revised stellar masses, and potential for interferometric observation, based on new photometric data.

Contribution

It offers the first detailed period variation analysis and revised system parameters of V994 Herculis using new photometric observations.

Findings

Orbital period of binaries is about 2.9 years, not 6.3 years.

System is nearly coplanar with an inclination of approximately 84 degrees.

The two binaries show slow apsidal motion with periods around 110-116 years.

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.