GK Boo and AE For: Two low-mass eclipsing binaries with dwarf companions

TL;DR

This study presents the first light curves and period analyses of two neglected low-mass eclipsing binaries, GK Boo and AE For, revealing their physical properties and long-term period changes.

Contribution

First light curves and period analyses of GK Boo and AE For, providing initial physical property estimates and insights into their long-term period variations.

Findings

Both systems contain low-mass stars of similar types.

GK Boo has a probable K3 spectral type for components and a late M companion.

AE For consists of two K7 stars with a possible brown dwarf companion.

Abstract

A study of late-type low-mass eclipsing binaries provides us with important information about the most common stars in the Universe. We obtain the first light curves and perform period analyses of two neglected eclipsing binaries GK Boo and AE For to reveal their basic physical properties. We performed both a period analysis of the times of the minima and a BVR light curve analysis. Many new times of minima for both the systems were derived and collected from the data obtained by automatic and robotic telescopes. This allowed us to study the long-term period changes in these systems for the first time. From the light curve analysis, we derived the first rough estimates of the physical properties of these systems. We find that the analyzed systems are somewhat similar to each other. Both contain low-mass components of similar types, both are close to the Sun, both have short orbital period, and both contain another low-mass companions on longer orbits of a few years. In the case of GK Boo, both components are probably of K3 spectral type, while the distant companion is probably a late M star. The light curve of GK Boo is asymmetric, which probably causes the shift in the secondary minima in the O-C diagram. System AE For comprises two K7 stars, and the third body is a possible brown dwarf with a minimal mass of only about 47 Jupiter Mass. We succeed in completing period and light curve analyses of both systems, although a more detailed spectroscopic analysis is needed to confirm the physical parameters of the components to a higher accuracy.