An ultraluminous nascent millisecond pulsar

If the ultraluminous source (ULX) M82 X-2 sustains its measured spin-up value of nu over dot = 10(-10) s(-2), it will become a millisecond pulsar in less than 10(5) yr. The observed (isotropic) luminosity of 10(40) erg s(-1) also supports the notion that the neutron star will spin up to a millisecond period upon accreting about 0.1 M circle dot-the reported hard X-ray luminosity of this ULX, together with the spin-up value, implies torques consistent with the accretion disc extending down to the vicinity of the stellar surface, as expected for low values of the stellar dipole magnetic field (B less than or similar to 10(9) G). This suggests a new channel of millisecond pulsar formation - in high-mass X-ray binaries - and may have implications for studies of gravitational waves, and possibly for the formation of low-mass black holes through accretion-induced collapse.