The ELODIE survey for northern extra-solar planets IV. HD196885, a close binary star with a 3.7-year planet

TL;DR

This paper reports the discovery of a new exoplanet orbiting HD 196885 A with a 1349-day period, along with a stellar companion, enhancing understanding of planetary systems in binary stars.

Contribution

First detection of a long-period exoplanet around HD 196885 A and characterization of its stellar companion, improving data on planets in binary systems.

Findings

Confirmed a 1349-day exoplanet orbit around HD 196885 A

Detected a stellar companion HD 196885 B and constrained its orbit

Refuted previous claim of a 386-day planet around the star

Abstract

Aims:We aim to significantly increase the number of detected extra-solar planets in a magnitude-limited sample to improve our knowledge of their orbital element distributions and thus obtain better constraints for planet-formation models. Methods: Radial-velocity data were taken at Haute-Provence Observatory (OHP, France) with the ELODIE echelle spectrograph. Results: We report the presence of a planet orbiting HD 196885 A, with an orbital period of 1349 days. This star was previously suggested to host a 386 -day planet, but we cannot confirm its existence. We also detect the presence of a stellar companion, HD 196885 B, and give some constraints on its orbit.