相关论文: AM CVn stars

Spiral density waves are thought to be excited in the accretion discs of accreting compact objects, including Cataclysmic Variable stars (CVs). Observational evidence has been obtained for a handful of systems in outburst over the last two…

We present new results for pulsating stars in general relativity. First we show that the so-called gravitational-wave modes of a neutron star can be excited when a gravitational wave impinges on the star. Numerical simulations suggest that…

We present the results of some recent research on AM CVn systems. We present: X-ray/UV observations made using XMM-Newton; the X-ray grating spectrum of RX J1914+24; preliminary results of a search for radio emission from AM CVn binaries,…

The AM Canum Venaticorum stars are rare interacting white dwarf binaries, whose formation and evolution are still poorly known. The Sloan Digital Sky Survey provides, for the first time, a sample of 6 AM CVn stars (out of a total population…

We discuss the model for the Galactic sample of the AM CVn systems with orbital periods P less than 1500 s, that can be detected in the optical and/or X-ray bands and may be resolved by the gravitational waves detector LISA. At P=3 to 10…

We report on the results from a five-night campaign of high-speed spectroscopy of the 17-minute binary AM Canum Venaticorum, obtained with the 4.2-m William Herschel Telescope on La Palma. We derive a mass ratio q=0.18+/-0.01 for AM CVn,…

We show that recent observations of the compact binary, AM CVn type system, ES Ceti are fully consistent with theoretical predictions of stable mass transfer moderated by angular momentum loss due to gravitational-wave radiation. One of the…

Neutron stars are excellent emitters of gravitational waves. Squeezing matter beyond nuclear densities invites exotic physical processes, many of which violently transfer large amounts of mass at relativistic velocities, disrupting…

We apply the new generation of theoretical models of low-mass stars to secondaries in CVs, focussing on systems above the period gap. The models confirm that the spectral type should be a good indicator of the donor mass. The orbital…

Surface asymmetries of accreting neutron stars are investigated for their mass quadrupole moment content. Though the amplitude of the gravitational waves from such asymmetries seem to be beyond the limit of detectability of the present…

We model cataclysmic variables (CVs) with solar metallicity donors ($X=0.7,\:Z=0.02$) that evolve to form AM CVn stars through the Evolved CV formation channel using various angular momentum loss mechanisms by magnetic braking…

We propose that when neutron stars in low-mass X-ray binaries accrete sufficient mass and become millisecond pulsars, the interiors of these stars may undergo phase transitions, which excite stellar radial oscillations. We show that the…

Recent theoretical and observational progress has substantially improved the definition of the lower main sequence and established a new basis for a comparison of main sequence stars and the secondaries in CVs. The evolutionary sequences of…

Black holes and weakly-magnetic accreting neutron stars show strong quasi-periodic variability over timescales that span a very wide range. This property offer us a unique opportunity to improve our understanding of basic physical processes…

AM CVn systems are a select group of ultracompact binaries with the shortest orbital periods of any known binary subclass; mass-transfer is likely from a low-mass (partially-)degenerate secondary onto a white dwarf primary, driven by…

We discuss different ways that neutron stars can generate gravitational waves, describe recent improvements in modelling the relevant scenarios in the context of improving detector sensitivity, and show how observations are beginning to…

Common-envelope evolution - where a star is engulfed by a companion - is a critical but poorly understood step in, e.g., the formation pathways for gravitational-wave sources. However, it has been extremely challenging to identify…

The results of recent photometric observations of suspected variable stars VV Cam and VW Cam and of fainter stars in their field of view are reported and compared to data available from scientific literature and public astronomical…

The evolution and stability of mass transfer of CO+He WD binaries are not well understood. Observationally they may emerge as AM CVn binaries and are important gravitational wave (GW) emitters. In this work, we have modeled the evolution of…

Star-disk interaction is thought to drive the angular momentum evolution of young stars. In this review, I present the latest results obtained on the rotational properties of low mass and very low mass pre-main sequence stars. I discuss the…