Close Binaries with Infrared Excess: Destroyers of Worlds?

Abstract

We present the results of a Spitzer photometric investigation into the IR excesses of close binary systems. In a sample of 10 objects, excesses in IRAC and MIPS24 bands implying the presence of warm dust are found for 3. For 2 objects we do not find excesses reported in earlier IRAS studies. We discuss the results in the context of the scenario suggested by Rhee and co-workers, in which warm dust is continuously created by destructive collisions between planetary bodies. A simple numerical model for the steady-state distribution of dust in one IR excess system shows a central clearing of radius 0.22 AU caused by dynamical perturbations from the binary star. This is consistent with the size of the central clearing derived from the Spitzer spectral energy distribution. We conclude that close binaries could be efficient "destroyers of worlds", lead to destabilize the orbits of their planetary progeny by magnetically-driven angular momentum loss and secular shrinkage of the binary separation.

Accepted by The Astrophysical Journal

References in corpus (9)

• The Complete Census of 70-um-Bright Debris Disks within the FEPS (Formation and Evolution of Planetary Systems) Spitzer Legacy Survey of Sun-like Stars
• The sdB+M Eclipsing System HW Virginis and its Circumbinary Planets
• Warm dust in the terrestrial planet zone of a sun-like Pleiad: collisions between planetary embryos?
• Spitzer/IRAC Limits to Planetary Companions of Fomalhaut and epsilon Eridani
• Spots, plages, and flares on lambda Andromedae and II Pegasi
• Long-term magnetic activity in close binary systems. I. Patterns of color variations
• Planetary systems around close binary stars: the case of the very dusty, Sun-like, spectroscopic binary BD+20 307
• On the Binary Nature of Dust-encircled BD+20 307
• An optical spectroscopic H-R diagram for low-mass stars and brown dwarfs in Orion

Cited by in corpus (6)

• Transient dust in warm debris disks - Detection of Fe-rich olivine grains
• A Sensitive Identification of Warm Debris Disks in the Solar Neighborhood Through Precise Calibration of Saturated WISE Photometry
• The Absence of Cold Dust and the Mineralogy and Origin of the Warm Dust Encircling BD +20 307
• A statistically significant lack of debris discs in medium separation binary systems
• Extending the FIP bias sample to magnetically active stars. Challenging the FIP bias paradigm?
• On the Nature of Rapidly Rotating Single Evolved Stars