The contact binary V344 Lacertae: is it a triple system?

TL;DR

This study analyzes the contact binary V344 Lac, revealing it is an A-subtype system with potential eccentric orbital oscillation caused by a third body, possibly a wide companion, and discusses its physical parameters and magnetic activity.

Contribution

It provides detailed photometric and spectroscopic analysis of V344 Lac, identifying a potential third body and explaining orbital oscillations through magnetic activity mechanisms.

Findings

V344 Lac is an A-subtype contact binary with a mass ratio of 0.387.

The system may have an eccentric orbital oscillation with a period of 12.4 years.

A third companion with an estimated mass of 0.79 solar masses may exist.

Abstract

The VRI passbands light curves of V344 Lac were presented and analyzed by using the latest version of the W-D code. The observed spectrum reveals that V344 Lac is not an A3 type but would be a later F type star according to the yielded temperature. The results of solution show that V344 Lac is an A-subtype contact binary, with a mediate photometric mass ratio of 0.387(0.003) and a mediate contact factor of 44.6(3.0)%. Based on the parallax given by Gaia, the parameters of the components are estimated as: M1 = 1.16 Ms, M2 = 0.45 Ms, R1 = 1.31 Rs, R2 = 0.88 Rs, L1 = 2.512 Ls, L2 = 1.057 Ls. The period investigation indicates that V344 Lac may have an eccentric orbital oscillation, with P3 = 12.4(0.5) yr, A3 = 0.0020(0.0002) d, and e = 0.38(0.16). Analysis shows such oscillation would be caused by a magnetic activity which can be explained by the Applegate mechanism. Meanwhile, according to the value of l3 and the estimated physical parameters of V344 Lac, the mass of the third companion may be 0.79 Ms. This third body could be a wide company.