The Physical Properties of HD 3651B: An Extrasolar Nemesis?

Abstract

I present detailed analysis of the near infrared spectrum of HD 3651B, a faint, co-moving wide companion to the nearby planet-hosting star HD 3651. These data confirm the companion as a brown dwarf with spectral type T8, consistent with the analysis of Luhman et al. Application of the semi-empirical technique of Burgasser, Burrows & Kirkpatrick indicates that HD 3651B has Teff = 790+/-30 K and log g = 5.0+/-0.3 for a metallicity of [M/H] = 0.12+/-0.04, consistent with a mass M = 0.033+/-0.013 M_sun and an age of 0.7-4.7 Gyr. The surface gravity, mass and age estimates of this source are all highly sensitive to the assumed metallicity; however, a supersolar metallicity is deduced by direct comparison of spectral models to the observed absolute fluxes. The age of HD 3651B is somewhat better constrained than that of the primary, with estimates for the latter ranging over ~2 Gyr to >12 Gyr. As a widely orbiting massive object to a known planetary system that could potentially harbor terrestrial planets in its habitable zone, HD 3651B may play the role of Nemesis in this system.

arXiv comment16 pages, 3 figures, accepted to ApJ Part 1; note that this article supersedes astro-ph/0609556

References in corpus (33)

• The Geneva-Copenhagen survey of the Solar neighbourhood: Ages, metallicities, and kinematic properties of 14,000 F and G dwarfs
• The Limiting Effects of Dust in Brown Dwarf Model Atmospheres
• Spectroscopic [Fe/H] for 98 extra-solar planet-host stars: Exploring the probability of planet formation
• Long-Term Stability of Planets in Binary Systems
• The Theory of Brown Dwarfs and Extrasolar Giant Planets
• Chromospheric CaII Emission in Nearby F, G, K, and M stars
• Near-Infrared Photometry and Spectroscopy of L and T Dwarfs: the Effects of Temperature, Clouds, and Gravity
• On the Luminosity of Young Jupiters
• A Unified Near Infrared Spectral Classification Scheme for T Dwarfs
• The Spectra of T Dwarfs I: Near-Infrared Data and Spectral Classification
• L and T Dwarf Models and the L to T Transition
• Stellar Companions to Stars with Planets
• Brown Dwarf Companions to G-type Stars. I: Gliese 417B and Gliese 584C
• The 2MASS Wide-Field T Dwarf Search. III. Seven New T Dwarfs and Other Cool Dwarf Discoveries
• Discovery of a Brown Dwarf Companion to Gliese 570ABC: A 2MASS T Dwarf Significantly Cooler than Gliese 229B
• Discovery of a candidate inner Oort cloud planetoid
• Discovery of Two T Dwarf Companions with the Spitzer Space Telescope
• Ammonia as a tracer of chemical equilibrium in the T7.5 dwarf Gliese 570D
• A Method for Determining the Physical Properties of the Coldest Known Brown Dwarfs
• Two Suns in The Sky: Stellar Multiplicity in Exoplanet Systems
• Calculations of the Far-Wing Line Profiles of Sodium and Potassium in the Atmospheres of Substellar-Mass Objects
• Statistical properties of exoplanets III. Planet properties and stellar multiplicity
• High Orbital Eccentricities of Extrasolar Planets Induced by the Kozai Mechanism
• Infrared Observations and Modeling of one of the Coolest T Dwarfs, Gl 570D
• Three Wide-Separation L dwarf Companions from the Two Micron All Sky Survey: Gl 337C, Gl 618.1B, and HD 89744B
• HD3651B: the first directly imaged brown dwarf companion of an exoplanet host star
• Prospects for Extrasolar "Earths" in Habitable Zones
• Measuring Fundamental Parameters of Substellar Objects. I: Surface Gravities
• Effects of Secular Interactions in Extrasolar Planetary Systems
• Survival of Terrestrial Planets in the Presence of Giant Planet Migration
• A Distant Stellar Companion in the Upsilon Andromedae System
• Astrometric Microlensing Constraints on a Massive Body in the Outer Solar System with Gaia
• On the Nature of the Unique H$\alpha$-Emitting T Dwarf 2MASS J12373919+6526148

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