Adaptive optics observations of the T10 ultracool dwarf UGPSJ072227.51-054031.2

Abstract

With a spectral type of T10, UGPS J072227.51-054031.2 is one of the coolest objects known to date in the solar neighborhood. Multiple systems are relatively common among early and mid-T dwarfs. We search for faint and close companions around UGPSJ072227.51-054031.2. We have obtained high spatial resolution images in the H and Ks bands using adaptive optics at the Very Large Telescope. With a Strehl ratio in the range 10-15%, the final images allow us to rule out the presence of a companion brighter than H<19.4mag at separation larger than 50mas, and H<21.4mag at separation larger than 0.1".