Related papers: Thermal-timescale mass transfer and magnetic CVs
In recent years there has been much interest in the nature of two stars, V407 Vul and RXJ0806+1527, which are widely thought to be binary white dwarfs of very short orbital period, 570 and 321 seconds respectively. As such they should be…
We analyse the K2 short cadence data of the intermediate polar FO Aqr and provide accurate and updated orbital and spin periodicities. We additionally find small spin period changes as a function of orbital phase of ~0.02 seconds…
We argue that the quiescent value of the viscosity parameter of the accretion disc in WZ Sge may be alpha_{cold}~0.01, in agreement with estimates of alpha_{cold} for other dwarf novae. Assuming the white dwarf in WZ Sge to be magnetic, we…
Many pulsating low-mass white-dwarf stars have been detected in the last years in the field of our Galaxy. Given that some of them exhibit multiperiodic variation of brightness, it is possible to probe their interiors through…
There are currently two open questions in white dwarf physics: why are massive dwarfs observed less often in astronomical surveys, and why have not any super-Chandrasekhar white dwarfs been found despite the discovery of more than a dozen…
One of the most important problems in the context of cataclysmic variables (CVs) is the lack of observations of systems with periods between 2 and 3.12 hours, known as the period gap. The orbital evolution of CVs with periods shorter than…
Ultramassive white dwarfs with masses $M\gtrsim 1.1\,{\rm M}_\odot$ probe extreme physics near the Chandrasekhar limit. Despite the rapid increase in observations, it is still unclear how many harbour carbon-oxygen (CO) versus oxygen-neon…
Accretion-driven spin-up of a magnetized white dwarf in a close binary system is discussed. We address a situation in which the magnetic field of the white dwarf is screening during the accretion phase and re-generating due to the field…
Accretion-induced collapse of massive white dwarfs (WDs) has been proposed to be an important channel to form binary millisecond pulsars (MSPs). Recent investigations on thermal timescale mass transfer in WD binaries demonstrate that the…
We present an eccentric precessing gas disk model designed to study the variable circumstellar absorption features detected for WD 1145+017, a metal polluted white dwarf with an actively disintegrating asteroid around it. This model,…
We present high speed photometry and high resolution spectroscopy of the eclipsing post common envelope binary QS Virginis (QS Vir). Our UVES spectra span multiple orbits over more than a year and reveal the presence of several large…
In this paper we present an analysis of near-infrared spectropolarimetric and velocimetric data of the young M dwarf AU Mic, collected with SPIRou at the Canada-France-Hawaii telescope from 2019 to 2022, mostly within the SPIRou Legacy…
The white dwarfs are promising laboratories for the study of cosmochronology and stellar evolution. Through observations of the pulsating white dwarfs, we can measure their internal structures and compositions, critical to understanding…
Hot white dwarfs with carbon-dominated atmospheres (hot DQs) are a cryptic class of white dwarfs. In addition to their deficiency of hydrogen and helium, most of these stars are highly magnetic, and a large fraction vary in luminosity. This…
We investigate the evolution and origin of small-scale chromospheric swirls by analyzing numerical simulations of the quiet solar atmosphere, using the radiative magnetohydrodynamic code CO$5$BOLD. We are interested in finding their…
The magnetism and rotation of white dwarf (WD) stars are investigated in relation to a hydromagnetic dynamo operating in the progenitor during shell burning phases. The downward pumping of angular momentum in the convective envelope, in…
This paper develops a generative statistical model for representing, modeling, and comparing the morphological evolution of biological cells undergoing motility. It uses the elastic shape analysis to separate cell kinematics (overall…
Two types of stars are known to have strong, large scale magnetic fields: the main sequence Ap stars and the magnetic white dwarfs. This suggest that the former might be the progenitors of the latter. In order to test this idea, I have…
Electron captures by atomic nuclei in dense matter are among the most important processes governing the late evolution of stars, limiting in particular the stability of white dwarfs. Despite considerable progress in the determination of the…
We report on the X-ray spectral and spatial evolution of the Symbiotic star R Aqr. Through a multi-epoch observational campaign performed with Chandra between 2017 and 2022, we study the X-ray emission of this binary system, composed of an…