Adaptive optics observations of the T10 ultracool dwarf UGPS J072227.51-054031.2

Abstract

Context. With a spectral type of T10, UGPS J072227.51-054031.2 is one of the coolest objects known to date in the solar neighborhood. Aims. Multiple systems are relatively common among early and mid-T dwarfs. We search for faint and close companions around UGPS J072227.51-054031.2. Methods. We have obtained high spatial resolution images in the H and Ks bands using adaptive optics at the Very Large Telescope. Results. 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≲19.4 mag at separation larger than 50 mas, and H ≲21.4 mag at separation larger than 0.1. © 2010 ESO.