The Absence of Cold Dust and the Mineralogy and Origin of the Warm Dust Encircling BD +20 307

Abstract

Spitzer Space Telescope photometry and spectroscopy of BD +20 307 show that all of the dust around this remarkable Gyr-old spectroscopic binary arises within 1 AU. No additional cold dust is needed to fit the infrared excess. Peaks in the 10 and 20 micron spectrum are well fit with small silicates that should be removed on a timescale of years from the system. This is the dustiest star known for its age, which is >1 Gyr. The dust cannot arise from a steady-state collisional cascade. A catastrophic collision of two rocky, planetary-scale bodies in the terrestrial zone is the most likely source for this warm dust because it does not require a reservoir of planetesimals in the outer system.

accepted to ApJ; 3 color figures

References in corpus (11)

• The Wide-field Infrared Survey Explorer (WISE): Mission Description and Initial On-orbit Performance
• Debris Disk Evolution Around A Stars
• Transience of hot dust around sun-like stars
• Debris disks around Sun-like stars
• Abundant Circumstellar Silica Dust and SiO Gas Created by a Giant Hypervelocity Collision in the ~12 Myr HD172555 System
• Evolution of Mid-IR Excess Around Sun-like Stars: Constraints on Models of Terrestrial Planet Formation
• Warm dust in the terrestrial planet zone of a sun-like Pleiad: collisions between planetary embryos?
• Planetary systems around close binary stars: the case of the very dusty, Sun-like, spectroscopic binary BD+20 307
• The discovery of new warm debris disks around F-type stars
• On the Binary Nature of Dust-encircled BD+20 307
• Close Binaries with Infrared Excess: Destroyers of Worlds?

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