Related papers: Rapid Evolution of the White Dwarf Pulsar AR Scorp…
Galactic short period double white dwarfs (DWD) are guaranteed gravitational wave (GW) sources for the next generation of space-based interferometers sensitive to low-frequency GWs (10^{-4}- 1 Hz). Here we investigate the possibility of…
PSR J1744-3922 is a binary pulsar exhibiting highly variable pulsed radio emission. We report on a statistical multi-frequency study of the pulsed radio flux variability which suggests that this phenomenon is extrinsic to the pulsar and…
We present new eclipse observations of the polar (i.e. semi-detached magnetic white dwarf + M-dwarf binary) HU Aqr, and mid-egress times for each eclipse, which continue to be observed increasingly early. Recent eclipses occurred more than…
We observe G117-B15A, the most precise optical clock known, to measure the rate of change of the main pulsation period of this blue-edge DAV white dwarf. Even though the obtained value is only within 1 sigma, Pdot = (2.3 +/- 1.4) x 10^{-15}…
We comment on a recent study reporting evidence for the general relativistic Lense-Thirring secular precession of the inclination $I$ of the orbital plane to the plane of the sky of the tight binary system PSR J1141-6545 made of a white…
Magnetic cataclysmic variables are close binaries which consist of a compact object - a white dwarf - and a red dwarf filling its Roche Lobe. Such systems are physical laboratories which enable study of the influence of magnetic fields on…
The observed fraction of pulsars with interpulses, their period distribution and the observed pulse width versus pulse period correlation is shown to be inconsistent with a model in which the angle alpha between the magnetic axis and the…
One of the least understood aspects of white dwarf evolution is the process by which they are formed. We are aided, however, by the fact that many H- and He-deficient pre-white dwarfs (PWDs) are multiperiodic g-mode pulsators. Pulsations in…
I introduce the two classes of pulsar, white-dwarf binaries, and describe for each what we have learned from a specific system, PSR J1012+5307 and PSR B0655+64, respectively, summarising what has been done, presenting new results, and…
Rotation-powered millisecond radio pulsars have been spun up to their present spin period by a $10^8$ - $10^9$ yr long X-ray-bright phase of accretion of matter and angular momentum in a low-to-intermediate mass binary system. Recently, the…
Polarimetry of IGR J1401-4306, a long period (12.7 hours), eclipsing intermediate polar and remnant of Nova Scorpii 1437 A.D., reveals periodic variations of optical circular polarization, confirming the system as the longest period…
This paper investigates the progenitors of Millisecond Pulsars (MSPs) with a distribution of long orbital periods (P_orb > 2 d), to show the link between white dwarf (WD) binaries and long orbits for some binary MSPs through the Accretion…
It has long been accepted that a possible mechanism for explaining the existence of magnetic white dwarfs is the merger of a binary white dwarf system, as there are viable mechanisms for producing sustainable magnetic fields within the…
The well-observed Crab pulsar helps one to uncover the underlying knowledge about pulsar evolution. The routine evolution model simultaneously describes the spin-down caused by the magnetic dipole radiation (MDR) and gravitational wave…
A modulation in the V-band with period 527.84+/-1.81 sec and amplitude 0.023 magnitude, attributable to the spin of the magnetic white dwarf primary star, has been detected in 7.5 hours of V-band CCD photometry data recorded during the…
We present time-series photometry during eruption of the extremely fast nova V1674 Herculis (Nova Her 2021). The 2021 light curve showed periodic signals at 0.152921(3) d and 501.486(5) s, which we interpret as respectively the orbital and…
We study accretion induced collapse of magnetized white dwarfs as an origin of millisecond pulsars. We apply magnetized accretion disk models to the pre-collapse accreting magnetic white dwarfs and calculate the white dwarf spin evolution.…
The binary system AR Sco contains an M star and the only known radio-pulsing white dwarf. The system shows emission from radio to X-rays, likely dominated by synchrotron radiation. The mechanism that produces most of this emission remains…
Using pulsewidth data for 872 isolated radio pulsars we test the hypothesis that pulsars evolve through a progressive narrowing of the emission cone combined with progressive alignment of the spin and magnetic axes. The new data provide…
AE Aquarii is a cataclysmic variable with the fastest known rotating magnetized white dwarf (P_spin = 33.08 s). Compared to many intermediate polars, AE Aquarii shows a soft X-ray spectrum with a very low luminosity (L_X ~ 10^{31} erg/s).…