WISEPA J171104.60+350036.8

WISE J1711+3500 is a binary consisting of a brown dwarf and a planetary-mass object or brown dwarf. Both objects are late T dwarfs.
WISE J1711+3500 was discovered in 2011 with the Wide-field Infrared Survey Explorer and with a spectrum from NASA IRTF as a T8 dwarf. In 2012 it was discovered that this object is a binary from imaging with the Keck telescope. The individual spectral types were estimated to be T8 for the primary and T9.5 for the secondary. The pair is separated by 15 ± 2 astronomical units. For an age of 1 billion years the masses are around 19–23 for the primary and around 8.1–10.7 for the secondary. For an age of 5 billion years the masses are around 44–48 for the primary and 20–26 for the secondary. The orbital period was poorly constrained, but is larger than 200 years.