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A New Brown Dwarf Desert? A Scarcity of Wide Ultracool Binaries

Peter R. Allen·David W. Koerner·Michael W. McElwain·Kelle L. Cruz·I. Neill Reid
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Abstract

We present the results of a deep-imaging search for wide companions to low-mass stars and brown dwarfs using NSFCam on IRTF. We searched a sample of 132 M7-L8 dwarfs to magnitude limits of $J \sim 20.5$ and $K \sim 18.5$, corresponding to secondary-primary mass ratios of $\sim 0.5$. No companions were found with separations between $2{\arcsec}$ to $31{\arcsec}$ ($\sim$40 AU to $\sim$1000 AU). This null result implies a wide companion frequency below 2.3% at the 95% confidence level within the sensitivity limits of the survey. Preliminary modeling efforts indicate that we could have detected 85% of companions more massive than $0.05 M_{\odot}$ and 50% above $0.03 M_{\odot}$.

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Peter R. Allen, David W. Koerner, Michael W. McElwain, Kelle L. Cruz, I. Neill Reid. 2006-10-25. A New Brown Dwarf Desert? A Scarcity of Wide Ultracool Binaries. https://doi.org/10.1086/510346

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