Multi-Epoch Observations of HD69830: High Resolution Spectroscopy and Limits to Variability

Abstract

The main-sequence solar-type star HD69830 has an unusually large amount of dusty debris orbiting close to three planets found via the radial velocity technique. In order to explore the dynamical interaction between the dust and planets, we have performed multi-epoch photometry and spectroscopy of the system over several orbits of the outer dust. We find no evidence for changes in either the dust amount or its composition, with upper limits of 5-7% (1 $\sigma$ per spectral element) on the variability of the {\it dust spectrum} over 1 year, 3.3% (1 $\sigma$) on the broad-band disk emission over 4 years, and 33% (1 $\sigma$) on the broad-band disk emission over 24 years. Detailed modeling of the spectrum of the emitting dust indicates that the dust is located outside of the orbits of the three planets and has a composition similar to main-belt, C-type asteroids asteroids in our solar system. Additionally, we find no evidence for a wide variety of gas species associated with the dust. Our new higher SNR spectra do not confirm our previously claimed detection of H${}_2$O ice leading to a firm conclusion that the debris can be associated with the break-up of one or more C-type asteroids formed in the dry, inner regions of the protoplanetary disk of the HD69830 system. The modeling of the spectral energy distribution and high spatial resolution observations in the mid-infrared are consistent with a $\sim$ 1 AU location for the emitting material.

References in corpus (17)

• Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics
• Transience of hot dust around sun-like stars
• Debris disks around Sun-like stars
• Spitzer IRS Spectroscopy of IRAS-Discovered Debris Disks
• H2O and OH gas in the terrestrial planet-forming zones of protoplanetary disks
• New Debris Disks Around Nearby Main Sequence Stars: Impact on The Direct Detection of Planets
• Steady-State Size Distributions for Collisional Populations: Analytical Solution with Size-Dependent Strength
• Ice Lines, Planetesimal Composition and Solid Surface Density in the Solar Nebula
• Abundant Circumstellar Silica Dust and SiO Gas Created by a Giant Hypervelocity Collision in the ~12 Myr HD172555 System
• A spectroscopy study of nearby late-type stars, possible members of stellar kinematic groups
• On the Nature of the Dust in the Debris Disk Around HD69830
• Formation and structure of the three Neptune-mass planets system around HD69830
• A near-infrared interferometric survey of debris disk stars. I. Probing the hot dust content around epsilon Eridani and tau Ceti with CHARA/FLUOR
• IRS Spectra of Solar-Type Stars: \break A Search for Asteroid Belt Analogs
• A near-infrared interferometric survey of debris disc stars. II. CHARA/FLUOR observations of six early-type dwarfs
• The nature of mid-infrared excesses from hot dust around Sun-like stars
• On the chromospheric activity of stars with planets

Cited by in corpus (21)

• DUst Around NEarby Stars. The survey observational results
• Herschel imaging of 61 Vir: implications for the prevalence of debris in low-mass planetary systems
• The bright end of the exo-Zodi luminosity function: Disk evolution and implications for exo-Earth detectability
• The SEEDS Direct Imaging Survey for Planets and Scattered Dust Emission in Debris Disk Systems
• Transient dust in warm debris disks - Detection of Fe-rich olivine grains
• The full spectral radiative properties of Proxima Centauri
• Confusion limited surveys: using WISE to quantify the rarity of warm dust around Kepler stars
• A statistically significant lack of debris discs in medium separation binary systems
• The infrared colors of the Sun
• Kuiper belt structure around nearby super-Earth host stars
• Variations on Debris Disks III. Collisional Cascades and Giant Impacts in the Terrestrial Zones of Solar-type Stars
• Spatially resolved imaging of the two-component eta Crv debris disk with Herschel
• A new sample of warm extreme debris disks from the ALLWISE catalog
• Resolving the terrestrial planet forming regions of HD113766 and HD172555 with MIDI
• Rocky Planet Formation: Quick and Neat
• Probing the Terrestrial Regions of Planetary Systems: Warm Debris Disks with Emission Features
• Infrared Spectroscopy of HR 4796A's Bright Outer Cometary Ring + Tenuous Inner Hot Dust Cloud
• Stellar Parameters for HD 69830, a Nearby Star with Three Neptune Mass Planets and an Asteroid Belt
• Planetary system architectures with low-mass inner planets: Direct imaging exploration of mature systems beyond 1 au
• Takeout and Delivery: Erasing the Dusty Signature of Late-stage Terrestrial Planet Formation
• Abundant sub-micron grains revealed in newly discovered extreme debris discs