Context :

Aims : New near-infrared large-area sky surveys ( e.g .
UKIDSS , CFBDS , WISE ) go deeper than 2MASS and aim at detecting brown dwarfs lurking in the Solar neighbourhood which are even fainter than the latest known T-type objects , so-called Y dwarfs .

Methods : Using UKIDSS data , we have found a faint brown dwarf candidate with very red optical-to-near-infrared but extremely blue near-infrared colours next to the recently discovered nearby L dwarf SDSS J141624.08 + 134826.7 .
We check if the two objects are co-moving by studying their parallactic and proper motion and compare the new object with known T dwarfs .

Results : The astrometric measurements are consistent with a physical pair ( sep \approx 75 AU ) at a distance d \approx 8 pc .
The extreme colour ( J - K \approx - 1.7 ) and absolute magnitude ( M _ { J } =17.78 \pm 0.46 and M _ { K } =19.45 \pm 0.52 ) make the new object appear as one of the coolest ( T _ { eff } \approx 600 K ) and nearest brown dwarfs , probably of late-T spectral type and possibly with a high surface gravity ( log g \approx 5.0 ) .

Conclusions :