Possible substellar companions in dwarf eclipsing binaries: SDSS J143547.87+373338.5, NSVS 7826147, and NSVS 14256825

TL;DR

This study analyzes eclipse timing variations in three dwarf binary systems to identify potential substellar companions, revealing possible brown dwarf or planetary third bodies through light-time effect modeling.

Contribution

First to derive or refine orbital periods of potential third bodies in these binaries using extensive eclipse timing data and light-time effect analysis.

Findings

Possible third bodies with 13 and 10-year orbits for two systems.

Minimum masses of third components are 17 MJ and 1.4 MJ.

Complex period variations in one system suggest multiple or unknown effects.

Abstract

We present the new results of our long-term observational project to detect the small variations in the orbital periods of low-mass and short-period eclipsing binaries. About 120 new precise mid-eclipse times were obtained for three relatively well-known dwarf eclipsing binaries: SDSS J143547.87+373338.5 (P = 0.126 d), NSVS 07826147 (0.162 d), and NSVS 14256825 (0.110 d). Observed-minus-calculated (O-C) diagrams of these systems were analyzed using all accurate timings, and, where possible, new parameters of the light-time effect were calculated. For the first time, we derive (or improve upon previous findings with regard to) the short orbital periods of 13 and 10 years of possible third bodies for SDSS J143547.87+373338.5 and NSVS 07826147, respectively. In these binaries, our data show that period variations can be modeled simply on the basis of a single circumbinary object. For the first two objects, we calculated the minimum mass of the third components to be 17 MJ, and 1.4 MJ respectively, which corresponds to the mass of a brown dwarf or a giant planet. For NSVS 14256825, the cyclical period changes caused by a single additional body cannot be confirmed by our recent eclipse time measurements. More complex behavior connected with two orbiting bodies, or yet unknown effects, should be taken into account.