Mid-Infrared Variability in Binary Brown Dwarfs

We have spatially resolved several nearby binary brown dwarfs and obtained midinfrared photometry with VISIR at the VLT. In particular, we have monitored ε Indi B and HD 130948 in several narrow-band MIR filters. The 10.5μm band is a probe to constrain nonequilibrium chemistry in the atmosphere of cool brown dwarfs.