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Forty-seven nearby main sequence stars were surveyed with the Keck Interferometer mid-infrared Nulling instrument (KIN) between 2008 and 2011, searching for faint resolved emission from exozodiacal dust. Observations of a subset of the sample have already been reported, focusing essentially on stars with no previously known dust (Millan-Gabet et al. 2011, hereafter Paper I). Here we extend this analysis to the whole KIN sample, including 22 more stars with known near- and/or far-infrared excesses. In addition to an analysis similar to that of Paper I, which was restricted to the 8 to 9µm spectral region, we present measurements obtained in all 10 spectral channels covering the 8 to 13 µm instrumental bandwidth. Based on the 8 to 9µm data alone, which provide the highest signal to noise measurements, only one star shows a large excess imputable to dust emission (η Crv), while 4 more show a significant ( 3σ) excess: β Leo, β UMa, ζ Lep and γ Oph. Overall, excesses detected by KIN are more frequent around A-type stars than later spectral types. A statistical analysis of the measurements further indicates that stars with known far-infrared (λ ≥ 70 µm) excesses have higher exozodiacal emission levels than stars with no previous indication of a cold outer disk. This statistical trend is observed
Mennesson et al. (Mon,) studied this question.
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