Talk abstract

Very low-mass binaries (VLMBs) with system masses $<0.2 M_\odot$ appear to be tighter and less frequent than binaries around higher-mass stars which are thought to form by disc fragmentation. I will show that disc fragmentation cannot occur in systems with masses $<0.2 M_\odot$ and so there should be a discontinuity in binary properties at this mass. I will speculate on how VLMBs might form.