Related papers: The Nonradially-Pulsating Primary of the Cataclysm…
Compact white dwarf (WD) binaries are important sources for space-based gravitational-wave (GW) observatories, and an increasing number of them are being identified by surveys like ZTF. We study the effects of nonlinear dynamical tides in…
We show that the blue 18.3-minute variable object discovered in the Galactic disk by the OGLE-III survey and named OGLE-GD-WD-0001 is a pulsating pre-white dwarf of PG 1159 spectral type. With an effective temperature of about 160,000 K it…
RR Lyrae stars (RRLs) are easy to identify thanks to their large photometric variation and short periods. All stars in the RRL instability strip are pulsators is often a hidden assumption in most stellar population studies using RRLs.…
The collection of high-quality photometric data by space telescopes is revolutionizing the area of white-dwarf asteroseismology. Among the different kinds of pulsating white dwarfs, there are those that have He-rich atmospheres, and they…
The nova-like variable AE Aquarii is a close binary system containing a red dwarf and a magnetized white dwarf rotating with the period of 33 seconds. A short spin period of the white dwarf is caused by an intensive mass exchange between…
By performing two-dimensional special relativistic (SR) magnetohydrodynamic simulations, we study possible signatures of gravitational waves (GWs) in the context of the collapsar model for long-duration gamma-ray bursts. In our SR…
We analyze the orbital period distribution of post-common-envelope white-dwarf-main-sequence (WDMS) binaries by cross-matching the new spectroscopic Gaia DR3 WDMS catalog with TESS light curves, and applying a uniform periodicity search and…
We present follow-up time-series photometric observations that confirm and extend the results of the significant discovery made by Barlow et al.(2008) that the Hot DQ white dwarfs SDSS J220029.08-074121.5 and SDSS J234843.30-094245.3 are…
Using a nonlocal time-dependent theory of convection, we have calculated the linear non-adiabatic oscillations of the Horizontal Branch (HB) stars, with both the dynamic and thermodynamic coupling between convection and oscillations…
Binary systems with ultrashort-period planetary-mass companions are expected to radiate continuous gravitational waves (GWs). However, earlier studies found that the detectability of such systems by the Laser Interferometer Space Antenna…
Our photometric monitoring revealed that DW Cnc, which was originally classified as a dwarf nova (V=15--17.5), remained at a bright state of Rc=14.68+/-0.07 for 61 days. In conjunction with optical spectra lacking a strong He II emission…
We present results from high speed photometry of a further thirteen faint cataclysmic variables. V356 Aql (Nova Aql 1936) shows flare-like outbursts with recurrence time scales ~ 3000 s, but no coherent periodicities. Aqr1 is an…
Aims: We present discovery observations of the new cataclysmic variable star (CV) 1RXS J092737.4-191529, as well as spectra and photometry of SY Vol. The selection technique that turned up these two CVs is described; it should be efficient…
A large number of white dwarf and donor masses in cataclysmic variables have been found via modelling the primary eclipse, a method that relies on untested assumptions. Recent measurements of the mass of the white dwarf in the cataclysmic…
As white-dwarf (WD) stars cool, they go through one or more stages of $g$(gravity)-mode pulsational instability, becoming multiperiodic variable stars. Stars passing through these instability domains allow astronomers to study their…
We present infrared JHK photometry of the cataclysmic variable SDSS J123813.73-033933.0 (SDSS1238)and analyze it along with optical spectroscopy, demonstrating that the binary system is most probably comprised of a massive white dwarf with…
Novae are cataclysmic variables driven by accretion of H-rich material onto a white-dwarf (WD) star from its low-mass main-sequence binary companion. New time-domain observational capabilities, such as the Palomar Transient Factory and…
We have discovered a detached pair of white dwarfs (WDs) with a 12.75 min orbital period and a 1,315 km/s radial velocity amplitude. We measure the full orbital parameters of the system using its light curve, which shows ellipsoidal…
We present results from full general relativistic three-dimensional hydrodynamics simulations of stellar core collapse of a 70 M$_\odot$ star with spectral neutrino transport. To investigate the impact of rotation on non-axisymmetric…
The internal structures of pulsating white dwarfs can be explored only with asteroseismology. Time series photometric observations were made for the pulsating DA white dwarf (ZZ Ceti star) WD~0246+326 during 9 nights in 2014 with a bi-site…