The study of triple systems V949 Cen, V358 Pup, and V1055 Sco

TL;DR

This study provides detailed photometric and spectroscopic analyses of three triple star systems, revealing their physical properties, orbital dynamics, and potential quadruple nature, using archival data and new observations.

Contribution

It offers the first detailed analysis of these systems, including new orbital parameters and insights into their gravitational binding and possible multiplicity.

Findings

V949 Cen has an orbital period of about 855 years.

V358 Pup exhibits slow apsidal motion.

V1055 Sco shows period variations suggesting a possible quadruple system.

Abstract

The systems V949 Cen, V358 Pup, and V1055 Sco are triples comprised of an eclipsing binary orbiting with a distant visual component on a much longer orbit. The first detailed photometric analysis of these interesting systems was performed using also the archival data from Hipparcos, ASAS, SuperWASP, OMC, and Pi Of The Sky surveys. The system V358~Pup was also analysed using the archival ESO spectra and the radial velocities were derived. The analyses of their light curves revealed the physical properties of the eclipsing components, while the interferometric data for these systems obtained during the last century show that the binaries are also weakly gravitationally bounded with the third components on much longer orbits. The photometry was carried out with the robotic telescope FRAM (part of the Pierre Auger Cosmic Ray Observatory), located in Argentina. The BVRI light curves were analysed with the PHOEBE program, yielding the basic physical parameters of the systems and their orbits. V949 Cen and V358 Pup were found to be detached systems, while V1055 Sco is probably a semi-detached one. V358 Pup shows a slow apsidal motion, while for V1055 Sco we detected some period variation probably due to the third body in the system, which cannot easily be attributed to the close visual companion. Therefore, we speculate that V1055 Sco can be a quadruple system. For V949 Cen a new orbit was computed, having the orbital period of about 855 yr.