Related papers: Infrared-excess white dwarfs in the Gaia 100 pc sa…
Aims. In this work we use the Gaia DR3 set of ultracool dwarf candidates and complement the Gaia spectrophotometry with additional photometry in order to characterise its global properties. This includes the inference of the distances,…
Mergers of double white dwarfs are considered significant potential progenitors of type Ia supernovae. Although there is no direct observational evidence to definitively determine the formation pathways of SNe Ia, studying the physical…
The upcoming NASA Transiting Exoplanet Survey Satellite (TESS) will obtain space-based uninterrupted light curves for a large sample of bright white dwarfs distributed across the entire sky, providing a very rich resource for…
The axion, a well-motivated hypothetical particle arising in extensions of the Standard Model, can be produced copiously within the hot, compact cores of white dwarf stars. The shape of the white dwarf luminosity function (WDLF) is a…
Results from a concerted Hubble Space Telescope (HST) survey of nearby white dwarfs for substellar objects is presented. A total of 7 DAZ white dwarfs with distances of $<$ 50 pc had high contrast and high spatial resolution NICMOS…
We present an analysis on the potential prevalence of mid infrared excesses in stars with and without planetary companions. Based on an extended database of stars detected with the ${\it WISE}$ satellite, we studied two stellar samples: one…
Hot subdwarfs are compact blue evolved objects, burning helium in their cores surrounded by a tiny hydrogen envelope. Most models agree on a common envelope binary evolution scenario in the Red Giant phase. However, the binarity rate for…
The aim of the Degenerate Objects around Degenerate Objects (DODO) survey is to search for very low mass brown dwarfs and extrasolar planets in wide orbits around white dwarfs via direct imaging. The direct detection of such companions…
Brown dwarf companions to white dwarfs are rare, but recent infra-red surveys are slowly reveal- ing examples. We present new observations of the post-common envelope binary WD0137-349, which reveals the effects of irradiation on the ~…
Ultra-compact double white dwarfs (DWDs) represent key targets for multi-messenger astrophysics, as they may be observed both through gravitational waves and the electromagnetic (EM) spectrum. The future Laser Interferometer Space Antenna…
We investigate whether nearby white dwarfs (WDs) can constrain dark matter (DM) interactions with ordinary matter. As experimental sensitivity improves, driven by the Gaia mission, the sample volume of nearby WDs has been increasing over…
Using a penalised maximum likelihood we estimate, for the first time, the velocity distribution of white dwarfs in the Solar neighbourhood. Our sample consists of 129 675 white dwarfs within 500 pc in Gaia Early Data Release 3 The white…
We report Spitzer Space Telescope photometry between 3.6 microns and 24 microns and spectroscopy between 5 microns and 15 microns of GD 362, a white dwarf with an effective temperature near 10,000 K that displays a remarkably high…
We have cross-correlated the 2dF QSO Redshift Survey (2QZ) white dwarf catalog with the GALEX 2nd Data Release and the Sloan Digital Sky Survey (SDSS) data release 5 to obtain ultraviolet photometry (FUV, NUV) for approximately 700 objects…
The third Gaia data release provides low-resolution spectra for around 200 million sources. It is expected that a sizeable fraction of them contain a white dwarf (WD), either isolated, or in a binary system with a main-sequence (MS)…
We increase the spectroscopic completeness of the 100 pc white dwarf sample in the SDSS footprint with 840 additional spectra. Our spectroscopy is 86% complete for white dwarfs hotter than $T_{\rm eff}= 5000$ K, where H$\alpha$ remains…
We report on the spectroscopic confirmation of 68 new bright ($G=13.5-17.2$ mag) and blue (pre-)white dwarfs (WDs). This finding has allowed us to almost double the number of the hottest ($T_{\mathrm{eff}} \geq 60$kK) known WDs brighter…
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…
One of the most promising space missions of ESA is the astrometric satellite Gaia, which will provide very precise astrometry and multicolour photometry, for all 1.3 billion objects to V~20, and radial velocities with accuracies of a few…
Determining the presence of widely separated substellar-mass companion is crucial to understand the dynamics of inner planets in extrasolar planetary systems (e.g. to explain their high mean eccentricity as inner planets are perturbed by…