New constraints on the structure of hot exozodiacal dust belts

Recent interferometric surveys of nearby main-sequence stars reveal a faint near-infrared excess in roughly two dozen systems, which is attributed to dust located very close to the stars. We model the near- and mid-infrared observations of nine systems to constrain the properties of this so-called hot exozodiacal dust. Our results show that the grains should have radii from 0.02−0.15 μm to 0.2−0.5 μm. The dust should be located within ~1 au from the star. Furthermore, we find a significant trend for the disc radius to increase with the stellar luminosity, with the possibility of a constant temperature of hot dust in all the systems studied.

Details: http://adsabs.harvard.edu/doi/10.1093/mnras/stx202

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