# No difference in orbital parameters of RV-detected giant planets between 0.1 and 5 au in single vs multi-stellar systems

## TL;DR

This study investigates whether stellar companions influence the orbital parameters of giant planets detected via radial velocity, finding no significant differences between single and multi-stellar systems within 0.1-5 au.

## Contribution

It provides the largest imaging survey to date of stellar companions around RV-detected giant planets and compares planetary properties in single versus multi-stellar systems.

## Key findings

- No difference in planet orbital parameters between single and multi-stellar systems.
- Confirmed new multi-stellar systems and characterized their orbital architectures.
- Published contrast curves to aid future long-period RV companion studies.

## Abstract

Our Keck/NIRC2 imaging survey searches for stellar companions around 144 systems with radial velocity (RV) detected giant planets to determine whether stellar binaries influence the planets' orbital parameters. This survey, the largest of its kind to date, finds eight confirmed binary systems and three confirmed triple systems. These include three new multi-stellar systems (HD 30856, HD 86081, and HD 207832) and three multi-stellar systems with newly confirmed common proper motion (HD 43691, HD 116029, and HD 164509). We combine these systems with seven RV planet-hosting multi-stellar systems from the literature in order to test for differences in the properties of planets with semimajor axes ranging between 0.1-5 au in single vs multi-stellar systems. We find no evidence that the presence or absence of stellar companions alters the distribution of planet properties in these systems. Although the observed stellar companions might influence the orbits of more distant planetary companions in these systems, our RV observations currently provide only weak constraints on the masses and orbital properties of planets beyond 5 au. In order to aid future efforts to characterize long period RV companions in these systems, we publish our contrast curves for all 144 targets. Using four years of astrometry for six hierarchical triple star systems hosting giant planets, we fit the orbits of the stellar companions in order to characterize the orbital architecture in these systems. We find that the orbital plane of the secondary and tertiary companions are inconsistent with an edge-on orbit in four out of six cases.