The age DE0823-49 is estimated to be between 80 million to 500 million years. This is consistant with the presence of lithium detected on DE0823-49A which implies it has a mass of less than 0.065 times the Sun’s mass. An object more massive that that is expected to burn away its lithium. Given that DE0823-49A is less than 0.065 times the Sun’s mass and still relatively hot, and that brown dwarfs cool gradually as they age, the age of DE0823-49A cannot exceed 500 million years. Since both DE0823-49A and DE0823-49B formed together, they should have the same age. With an age of less than 500 million years, DE0823-49 is a pair of juvenile brown dwarfs. It is also relatively nearby, located only 67.5 light years away.
Sahlmann et al. (2015), “DE0823-49 is a juvenile binary brown dwarf at 20.7 pc”, arXiv:1505.07972 [astro-ph.SR]