Adaptive optics observations of the T10 ultracool dwarf UGPS J072227.51-054031.2
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 01.