Binary KBOs

• There are now known six binary KBOs (besides Pluto).
  • First discovered 12/00 (Veillet with CHFT).
  
  
• Semi-major axes very large (~10,000 km)
  • Obviously could be observational biases.
  • Orbital velocity only ~3m/s!
  
  
• Thus, they are very easy to disrupt.
  
  
• So, locations may place important constraints on the history of the Kuiper belt.
  
  
  • Binary forming impact could(would?) kick KBO out of resonance.
    ....... Binary formed before resonance (Stern).
    
    
  • Whatever cause resonance trapping preserved binaries.
    ....... Migration is still OK.
    
    
  • All known main belt binary KBOs are part of cold population. Statistically significant?
    ....... Perhaps excitation process destroys binaries.