Related papers: Luminosity function suggests up to 100 white dwarf…

Infrared (IR) excess observed around white dwarfs (WDs) is typically attributed to companions or debris disks. These systems are interesting because they offer a unique opportunity to study the late stages of stellar evolution and the…

Taking advantage of the now available Gaia EDR3 parallaxes, we carry out an archival {\it Hubble Space Telescope} (HST) far ultraviolet spectroscopic analysis of 10 cataclysmic variable systems, including 5 carefully selected eclipsing…

Context. White dwarf-main sequence (WDMS) binaries are used to study several different important open problems in modern astrophysics. Aims. The Sloan Digital Sky Survey (SDSS) identified the largest catalogue of WDMS binaries currently…

Many open clusters have a deficit of observed white dwarfs (WDs) compared with predictions of the number of stars to have evolved into WDs. We evaluate the number of WDs produced in open clusters and the number of those WDS detectable using…

The white dwarf luminosity function is an important tool to understand the properties of the Solar neighborhood, like its star formation history, and its age. Here we present a population synthesis study of the white dwarf population within…

The presence of infrared excess flux observed in white dwarfs (WDs) is related to the existence of debris disks or substellar companions. These systems provide important clues in the study of extrasolar planetary material and binary…

With targeted imaging of groups in the local volume, the regions of collapse around bright galaxies can be clearly identified by the distribution of dwarfs and luminosity functions can be established to very faint levels. In the case of the…

We examine the claim by Oppenheimer et al. (2001) that the local halo density of white dwarfs is an order of magnitude higher than previously thought. As it stands, the observational data support the presence of a kinematically distinct…

Binaries containing compact objects, if viewed close to edge on, can produce periodic brightening events under certain conditions on the masses, radii, and binary separation. Such flares are caused by one object gravitational lensing the…

We investigate the membership in double, triple or higher-order-multiplicity systems of 54 pairs with at least one bright M dwarf in the solar neighbourhood. These M dwarfs are potential targets of radial-velocity surveys for exoplanets. We…

We describe new radial velocity and X-ray observations of extremely low-mass white dwarfs (ELM WDs, ~0.2 Msol) in the Sloan Digital Sky Survey Data Release 4 and the MMT Hypervelocity Star survey. We identify four new short period binaries,…

We conducted a search for new ultracool companions to nearby white dwarfs using multiple methods, including the analysis of colors and examination of images in both the optical and the infrared. Through this process, we identified fifty-one…

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…

The galactic halo likely grew over time in part by assembling smaller galaxies, the so-called building blocks. We investigate if the properties of these building blocks are reflected in the halo white dwarf (WD) population in the Solar…

We report the discovery of the fifth self-lensing binary in which a low-mass white dwarf (WD) gravitationally magnifies its 15th magnitude G-star companion, KIC 8145411, during eclipses. The system was identified from a pair of such…

We present a magnitude and proper motion limited catalogue of ~10,000 white dwarf candidates, obtained from the SuperCOSMOS Sky Survey by means of reduced proper motion selection. This catalogue extends to magnitudes r~19.75 and proper…

We have carried out a search for massive white dwarfs (WDs) in the direction of young open star clusters using the Gaia DR2 database. The aim of this survey was to provide robust data for new and previously known high-mass WDs regarding…

We present radial velocity observations of four extremely low-mass (0.2 Msol) white dwarfs. All four stars show peak-to-peak radial velocity variations of 540 - 710 km/s with 1.0 - 5.9 hr periods. The optical photometry rules out…

We have presented 309 new white-dwarf (WD) + main-sequence (MS) star binaries identified from the Sloan Digital Sky Survey (SDSS) Tenth Data Release (DR10). The majority of them consist of a white dwarf and a low-mass secondary (typically M…

We place observational constraints on a recently proposed Galactic population, dubbed the shroud (Gyuk & Gates 1999, Gates & Gyuk 2001). The shroud would be a very thick Galactic disk of low luminosity objects, most likely old white dwarfs,…