• The halo contains the majority of the mass of our galaxy
• What makes up the halo?
  1. ordinary stars
  2. dark matter
  3. MACHOs -- which might be white dwarfs
• Microlensing studies provide some constraints on the number of MACHOs in the halo ...
• But we need more data on the properties of white dwarfs in the halo
• Alas, they are hard to find, because white dwarfs give off very little light and most stars in the halo are very far away

Back ...... Forth