We examine the recent results of the MACHO collaboration towards the Large Magellanic Cloud ( Alcock et al .
1996 ) in terms of a halo brown dwarf or white dwarf population .
The possibility for most of the microlensing events to be due to brown dwarfs is totally excluded by large-scale kinematic properties .
The white dwarf scenario is examined in details in the context of the most recent white dwarf cooling theory ( Segretain et al .
1994 ) which includes explicitely the extra source of energy due to carbon-oxygen differentiation at crystallization , and the subsequent Debye cooling .
We show that the observational constraints arising from the luminosity function of high-velocity white dwarfs in the solar neighborhood and from the recent HST deep field counts are consistent with a white dwarf contribution to the halo missing mass as large as 50 % , provided i ) an IMF strongly peaked around \sim 1.7 M _ { \odot } and ii ) a halo age older than \sim 18 Gyr .

Subject headings : stars : low-mass , brown dwarfs — stars : white dwarfs — stars : luminosity function , mass function — The Galaxy : halo — dark matter