The Debris Disk of Solar Analogue $\tau$ Ceti: Herschel Observations and Dynamical Simulations of the Proposed Multiplanet System

Abstract

$\tau$ Ceti is a nearby, mature G-type star very similar to our Sun, with a massive Kuiper Belt analogue (Greaves et al. 2004) and possible multiplanet system (Tuomi et al. 2013) that has been compared to our Solar System. We present Herschel Space Observatory images of the debris disk, finding the disk is resolved at 70 and 160 microns, and marginally resolved at 250 microns. The Herschel images and infrared photometry from the literature are best modelled using a wide dust annulus with an inner edge between 1-10 AU and an outer edge at ~55 AU, inclined from face-on by 35$\pm$10 degrees, and with no significant azimuthal structure. We model the proposed tightly-packed planetary system of five super-Earths and find that the innermost dynamically stable disk orbits are consistent with the inner edge found by the observations. The photometric modelling, however, cannot rule out a disk inner edge as close to the star as 1 AU, though larger distances produce a better fit to the data. Dynamical modelling shows that the 5 planet system is stable with the addition of a Neptune or smaller mass planet on an orbit outside 5 AU, where the Tuomi et al. analysis would not have detected a planet of this mass.

accepted to MNRAS

References in corpus (7)

• Direct Imaging of Multiple Planets Orbiting the Star HR 8799
• Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics
• Spitzer IRS Spectroscopy of IRAS-Discovered Debris Disks
• Alignment of the stellar spin with the orbits of a three-planet system
• Bayesian search for low-mass planets around nearby M dwarfs. Estimates for occurrence rate based on global detectability statistics
• Resolved Debris Discs Around A Stars in the Herschel DEBRIS Survey
• A near-infrared interferometric survey of debris disk stars. I. Probing the hot dust content around epsilon Eridani and tau Ceti with CHARA/FLUOR

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• Weakened Magnetic Braking Signals the Collapse of the Global Stellar Dynamo
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• 94 Ceti: a triple star with a planet and dust disc
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