Upper Limits on Stellar Companions to the Kepler-34 and Kepler-35 Systems

TL;DR

This study uses high-precision radial velocity measurements to set upper limits on potential third stellar companions in the Kepler-34 and Kepler-35 systems, constraining their possible masses and orbital periods.

Contribution

It provides the first long-term radial velocity constraints on third stellar companions in these systems, improving previous limits with nearly a decade of new data.

Findings

Ruled out coplanar stellar companions of 0.12 M_sun at periods ≤ 52 years for Kepler-34

Ruled out stellar companions of 0.13 M_sun at periods ≤ 55 years for Kepler-35

Future high-precision RV instruments can lower these mass limits further.

Abstract

We obtained new spectra of Kepler-34 and Kepler-35 with Keck-HIRES, nearly a decade after these systems were originally characterized with this spectrograph and other instruments, to search for RV trends from a potential third stellar-mass companion at long periods. For Kepler-34, we rule out coplanar stellar masses as low as $0.12 M_\odot$ at an orbital period of $\lesssim 52$ years. For Kepler-35, we rule out stellar masses of $0.13 M_\odot$ at orbital periods of $\lesssim 55$ years. Highly stable, extreme precision RV instruments, as well as improved methodologies in characterizing double-lined spectroscopic binaries that come with these new instruments, will provide an opportunity to push these mass limits lower in the future.