Fundamental Parameters of the Exoplanet Host K Giant Star iota Draconis from the CHARA Array

TL;DR

This study precisely measured the physical parameters of the exoplanet host star iota Draconis using interferometry, combined with stellar oscillation data, to refine the star and exoplanet's masses and habitable zone location.

Contribution

The paper presents new interferometric measurements of iota Draconis's angular diameter and derives updated stellar and planetary parameters, improving understanding of this exoplanet system.

Findings

Star's mass: 1.82 +/- 0.23 M_Sun

Exoplanet's minimum mass: 12.6 +/- 1.1 M_Jupiter

Habitable zone is outside the star-planet separation

Abstract

We measured the angular diameter of the exoplanet host star iota Dra with Georgia State University's Center for High Angular Resolution Astronomy (CHARA) Array interferometer, and, using the star's parallax and photometry from the literature, calculated its physical radius and effective temperature. We then combined our results with stellar oscillation frequencies from Zechmeister et al. (2008) and orbital elements from Kane et al. (2010) to determine the masses for the star and exoplanet. Our value for the central star's mass is 1.82 +/- 0.23 M_Sun, which means the exoplanet's minimum mass is 12.6 +/- 1.1 M_Jupiter. Using our new effective temperature, we recalculated the habitable zone for the system, though it is well outside the star-planet separation.