AXION CYCLOTRON EMISSIVITY OF MAGNETIZED WHITE-DWARFS AND NEUTRON-STARS

The energy loss rate of a magnetized electron gas emitting axions a du e to the process e(-)-->e(-)+a is derived for arbitrary magnetic field strength B. Requiring that for a strongly magnetized neutron star the axion luminosity is smaller than the neutrino luminosity we obtain th e bound g(ae) less than or similar to 10(-10) for the axion electron c oupling constant. This limit is considerably weaker than the bound der ived earlier by Borisov and Grishina using the same method. Applying a similar argument to magnetic white dwarf stars results in the more st ringent bound g(ae)less than or similar to 9x10(-13)(T/10(7)K)(5/4)(B/ 10(10)G)(-2), where T is the internal temperature of the white dwarf.