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A. R. King M. E. Beer D. J. Rolfe K. Schenker J. M. Skipp 《Monthly notices of the Royal Astronomical Society》2005,358(4):1501-1504
We consider the population of black widow pulsars (BWPs). The large majority of these are members of globular clusters. For minimum companion masses ≲0.1 M⊙ , adiabatic evolution and consequent mass loss under gravitational radiation appear to provide a coherent explanation of all observable properties. We suggest that the group of BWPs with minimum companion masses ≳0.1 M⊙ are systems relaxing to equilibrium after a relatively recent capture event. We point out that all binary millisecond pulsars (MSPs) with orbital periods P ≲ 10 h are BWPs (our line of sight allows us to see the eclipses in 10 out of 16 cases). This implies that recycled MSPs emit either in a wide fan beam or a pencil beam close to the spin plane. Simple evolutionary ideas favour a fan beam. 相似文献
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L. G. Luk’yanov 《Astronomy Letters》2005,31(8):563-568
We consider the conservative two-body problem with a constant total mass, but with variable individual masses. The problem is shown to be completely integrable for any mass variation law. The Keplerian motion known for the classical two-body problem with constant masses remains valid for the relative motion of the bodies. The absolute motions of the bodies depend on the center-of-mass motion. Hitherto unknown quadratures that depend on the mass variation law were derived for the integrals of motion of the center of mass. We consider some of the laws that are of interest in studying the motion of close binary stars with mass transfer. 相似文献
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M. R. Truss 《Monthly notices of the Royal Astronomical Society》2005,356(4):1471-1476
The 2001 outburst of WZ Sagittae has shown the most compelling evidence yet for an enhancement of the mass-transfer rate from the donor star during a dwarf nova outburst in the form of hotspot brightening. I show that, even in this extreme case, the brightening can be attributed to tidal heating near the interaction point of an accretion stream with the expanding edge of an eccentric accretion disc, with no need at all for an increase in the mass-transfer rate. Furthermore, I confirm previous suggestions that an increase in mass-transfer rate through the stream damps any eccentricity in an accretion disc and suppresses the appearance of superhumps, in contradiction to observations. Tidal heating is expected to be most significant in systems with small mass ratios. It follows that systems like WZ Sagittae – which has a tiny mass ratio – are those most likely to show a brightening in the hotspot region. 相似文献
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