Know the Star, Know the Planet. II. Speckle Interferometry of Exoplanet Host Stars

TL;DR

This study uses speckle interferometry to observe exoplanet host stars, revealing new binary companions and confirming known pairs, which aids in understanding their environments and potential influences on exoplanets.

Contribution

It provides new high-resolution observations of exoplanet host stars, discovering ten new binary pairs and confirming sixty others, enhancing knowledge of their multiplicity.

Findings

HD 8673 has a companion, but its nature is uncertain.

Ten new binary pairs were resolved for the first time.

Sixty binary pairs were confirmed.

Abstract

A study of the host stars to exoplanets is important to understanding their environment. To that end, we report new speckle observations of a sample of exoplanet host primaries. The bright exoplanet host HD 8673 (= HIP 6702) is revealed to have a companion, although at this time we cannot definitively establish the companion as physical or optical. The observing lists for planet searches and for these observations have for the most part been pre-screened for known duplicity, so the detected binary fraction is lower than what would otherwise be expected. Therefore, a large number of double stars were observed contemporaneously for verification and quality control purposes, to ensure the lack of detection of companions for exoplanet hosts was valid. In these additional observations, ten pairs are resolved for the first time and sixty pairs are confirmed. These observations were obtained with the USNO speckle camera on the NOAO 4m telescopes at both KPNO and CTIO from 2001 to 2010.