High-Resolution Spectroscopy of the Planetary Host HD 13189: Highly-Evolved and Metal-Poor

Abstract

We report on the abundances of 13 elements in the planetary host HD 13189, a massive giant star. Abundances are found to be sub-solar, with [Fe/H] = -0.58 +/- 0.04$; HD 13189 is one of the most metal-poor planetary hosts yet discovered. Abundance ratios relative to Fe show no peculiarities with respect to random field stars. A census of metallicities of the seven currently known planet-harboring giants results in a distribution that is more metal-poor than the well-known metal-rich distribution of main sequence (MS) planetary hosts. This finding is discussed in terms of accretion of H-depleted material, one of the possible mechanisms responsible for the high-metallicity distribution of MS stars with planets. We estimate the mass of the HD 13189 progenitor to be 3.5 M_sun but cannot constrain this value to better than 2-6 M_sun. A stellar mass of 3.5 M_sun implies a planetary mass of m sin i = 14.0 +/- 0.8 M_J, placing the companion at the planet/brown dwarf boundary. Given its physical characteristics, the HD 13189 system is potentially unique among planetary systems, and its continued investigation should provide invaluable data to extrasolar planetary research.

arXiv comment14 pages, 2 figures; Accepted for publication in ApJ Letters

References in corpus (17)

• Evolutionary tracks and isochrones for low- and intermediate-mass stars: from 0.15 to 7 M_sun, and from Z=0.0004 to 0.03
• The 'Forbidden' Abundance of Oxygen in the Sun
• Spectroscopic [Fe/H] for 98 extra-solar planet-host stars: Exploring the probability of planet formation
• The formation and retention of gas giant planets around stars with a range of metallicities
• Statistical properties of exoplanets II. Metallicity, orbital parameters, and space velocities
• Spectroscopic metallicities for planet-host stars: extending the samples
• A companion to AB Pic at the planet/brown dwarf boundary
• The Mass of the Convective Zone in FGK Main Sequence Stars and the Effect of Accreted Planetary Material on Apparent Metallicity Determinations
• Abundances and Kinematics of Field Stars II: Kinematics and Abundance Relationships
• Searching for Planets in the Hyades V: Limits on Planet Detection in the Presence of Stellar Activity
• The Abundance Distribution in the Extrasolar-Planet Host Star HD19994
• A Dedicated M-Dwarf Planet Search Using The Hobby-Eberly Telescope
• A substellar companion around the intermediate-mass giant star HD 11977
• A Search for ${}^6$Li in Stars with Planets
• New measurement of the Lithium-6/Lithium-7 isotopic ratio in the extra-solar planet host star HD82943 and line blending in the Li 6708 A region
• Planet accretion and the abundances of lithium isotopes
• Quantifying orbital migration from exoplanet statistics and host metallicities

Cited by in corpus (23)

• Basic physical parameters of a selected sample of evolved stars
• Retired A Stars and Their Companions: Exoplanets Orbiting Three Intermediate-Mass Subgiants
• Precise radial velocities of giant stars. III. Spectroscopic stellar parameters
• Retired A Stars and Their Companions. III. Comparing the Mass-Period Distributions of Planets Around A-Type Stars and Sun-Like Stars
• Evolved stars hint to an external origin of enhanced metallicity in planet-hosting stars
• Evidence of an Upper Bound on the Masses of Planets and its Implications for Giant Planet Formation
• Stellar parameters and chemical abundances of 223 evolved stars with and without planets
• The Pan-Pacific Planet Search. I. A Giant Planet Orbiting 7 CMa
• The properties of planets around giant stars
• Planetary Formation Scenarios Revistied: Core-Accretion Versus Disk Instability
• The metallicity signature of evolved stars with planets
• Metallicities of Planet Hosting Stars: A Sample of Giants and Subgiants
• Consistent metallicity scale for cool dwarfs and giants. A benchmark test using the Hyades
• Discovery of a planet around the K giant star 4 UMa
• Planetary companions around the K giant stars 11 UMi and HD 32518
• Evolved stars and the origin of abundance trends in planet hosts
• Connecting substellar and stellar formation. The role of the host star's metallicity
• Planetary companion candidates around the K giant stars 42 Dra and HD 139357
• Chemical fingerprints of hot Jupiter planet formation
• Ruling Out Possible Secondary Stars to Exoplanet Host Stars Using the CHARA Array
• Searching for chemical signatures of brown dwarf formation
• Emerging trends in metallicity and lithium properties of debris disc stars
• Quantization of Planetary Systems and its Dependency on Stellar Rotation