Baryonic dark matter

Baryonic dark matter is the dark matter (i.e. matter that doesn't emit light) composed of baryons, i.e. protons and neutrons. Candidates for baryonic dark matter are brown dwarfs and compact stellar objects.

The total amount of dark matter can be calculated from big bang nucleosynthesis, and observations of the cosmic microwave background. Both tell that the amount of baryonic dark matter is much smaller that the total amount of dark matter.