RX J0648.0--4418: the fastest-spinning white dwarf

摘要

RX J0648.0-4418 is a post common-envelope X-ray binary composed of a hotsubdwarf and one of the most massive white dwarfs with a dynamical massmeasurement (1.28+/-0.05 M_sun). This white dwarf, with a spin period of 13.2s, rotates more than twice faster than the white dwarf in the cataclysmicvariable AE Aqr. The current properties of these two binaries, as well as theirfuture evolution, are quite different, despite both contain a fast-spinningwhite dwarf. RX J0648.0-4418 could be the progenitor of either a Type Iasupernova or of a non-recycled millisecond pulsars.