Related papers: New Close Binary Systems from the SDSS-I (Data Rel…

We present a near-infrared photometric search for unresolved substellar companions and debris disks around white dwarfs in the UKIRT Infrared Deep Sky Survey Large Area Survey. We cross-correlate the SDSS DR4 and McCook & Sion catalogues of…

We present a catalogue of 507 cataclysmic variables (CVs) observed in SDSS I to IV including 70 new classifications collated from multiple archival data sets. This represents the largest sample of CVs with high-quality and homogeneous…

Magnetic white dwarfs (MWDs) are key to understanding the origin and evolution of magnetic fields in compact stars. While large spectroscopic surveys such as SDSS have greatly expanded the known sample, the potential of LAMOST has not yet…

The magnetic white dwarfs (MWDs) are found either isolated or in interacting binaries. They divide into two groups: a high field group (0.1-1,000MegaGauss) comprising some 13% of all white dwarfs (WDs), and a low field group (B<0.1MG) whose…

Recent studies of the stellar population in the solar neighborhood (<20 pc) suggest that there are undetected white dwarfs (WDs) in multiple systems with main sequence companions. Detecting these hidden stars and obtaining a more complete…

We report the discovery of five very cool white dwarfs in the Sloan Digital Sky Survey (SDSS). Four are ultracool, exhibiting strong collision induced absorption (CIA) from molecular hydrogen and are similar in color to the three previously…

Among the 28,000 targeted stars in K2 Field 10 is the white dwarf WD 1202-024 (EPIC 201283111), first noted in the SDSS survey (SDSS 120515.80-024222.7). We have found that this hot white dwarf (Teff = 22,640 K) is in a very close orbit (P…

Multiplicity studies greatly benefit from focusing on M dwarfs because they are often paired in a variety of configurations with both stellar and substellar objects, including exoplanets. We aim to address the observed multiplicity of M…

In recent years, approximately 150 low-mass white dwarfs (WDs), typically with masses below 0.4 solar masses, have been discovered. Observational evidence indicates that most of these low-mass WDs are found in binary systems, supporting…

We present the first results of a dedicated search for pulsating white dwarfs (WDs) in detached white dwarf plus main-sequence binaries. Candidate systems were selected from a catalogue of WD+MS binaries, based on the surface gravities and…

We present new radial velocity and X-ray observations of extremely low-mass (ELM, 0.2 Msol) white dwarf candidates in the Sloan Digital Sky Survey (SDSS) Data Release 7 area. We identify seven new binary systems with 1-18 h orbital periods.…

The first full year of operation following the commissioning year of the Sloan Digital Sky Survey has revealed a wide variety of newly discovered cataclysmic variables. We show the SDSS spectra of forty-two cataclysmic variables observed in…

Using a filter in the GROWTH Marshal based on color and the amplitude and the timescale of variability, we have identified 372 objects as known or candidate cataclysmic variables (CVs) during the second year of operation of the Zwicky…

White dwarfs are excellent research laboratories as they reach temperatures, pressures, and magnetic fields that are unattainable on Earth. To better understand how these three physical parameters interact with each other and with other…

We model the population of double white dwarfs in the Galaxy and find a better agreement with observations compared to earlier studies, due to two modifications. The first is the treatment of the first phase of unstable mass transfer and…

White dwarf-main sequence (WDMS) binary systems are essential probes for understanding binary stellar evolution and play a pivotal role in constraining theoretical models of various transient phenomena. In this study, we construct a catalog…

Cataclysmic Variables (CV) are close binary systems, in which the primary, the more massive star, is a white dwarf. CVs usually exhibit a number of periodicities, most of which are now understood. However, recently, a new phenomenon was…

We conduct a model atmosphere analysis on all magnetic white dwarfs in the SDSS 100 pc sample. We have 163 magnetic targets in this sample, 87 of which are new discoveries, making this the largest volume-limited survey of magnetic white…

We examine the applicability of the initial-to-final mass relation (IFMR) for white dwarfs (WDs) in intermediate-separation binary systems (approximately 1 AU), using astrometric binaries identified in open clusters from Gaia DR3. A careful…

The origin of magnetic white dwarfs (MWDs) has been a long-standing puzzle. Proposed origin mechanisms have included: fossil fields frozen in from the progenitor convective core; a dynamo in the progenitor envelope; crystallization dynamos…