Probing the Impact of Stellar Duplicity on Planet Occurrence with Spectroscopic and Imaging Observations

TL;DR

This study investigates how the presence of close stellar companions affects planet formation and occurrence, using adaptive optics imaging and radial-velocity monitoring to provide new observational constraints.

Contribution

It presents the first observational evidence that planet occurrence decreases in binaries closer than approximately 120 AU, using combined imaging and spectroscopic data.

Findings

Planet occurrence is reduced in binaries closer than ~120 AU.

Adaptive optics imaging and radial-velocity monitoring effectively detect planets in binary systems.

Ongoing research aims to refine constraints on planet formation in close binaries.

Abstract

Although it is commonly agreed that the presence of a close stellar companion is likely to affect planet formation and evolution, the precise effects and their actual impact on planet occurrence and properties are still debated. In particular, observational constraints are sparse, a consequence of the discrimination against close binaries in Doppler planet searches. To bring observational constraints on the occurrence and properties of planets in binaries and multiple stars, we have been conducting two dedicated observing programs using both adaptive optics imaging and radial-velocity monitoring. In this chapter we explain our approach and present preliminary results from these two programs. A simplified statistical analysis of the data from our VLT/NACO imaging survey brings the first observational evidence that the occurrence of planets is reduced in binaries closer than ~120 AU. On the radial-velocity side, current results confirm that the use of two-dimensional correlation allows to search for circumprimary giant planets in many types of spectroscopic binaries. Definitive results from our ongoing planet search in spectroscopic binaries should yield important constraints on the closest binaries susceptible of hosting circumprimary giant planets.