Related papers: Discovery of two bright DO-type white dwarfs

The New Luyten Two-Tenths catalog contains a large number of high-proper motion white dwarf candidates that remain to be spectroscopically confirmed. We present new spectroscopic observations as well as SDSS archival spectra of 49 white…

We present the discovery of two nearby L dwarfs from our 2MASS proper motion search, which uses multi-epoch 2MASS observations covering ~4700 square degrees of sky. 2MASS J18212815+1414010 and 2MASS J21481628+4003593 were overlooked by…

We present an analysis of spectroscopic and photometric observations of cool DQ white dwarfs based on improved model atmosphere calculations. In particular, we revise the atmospheric parameters of the trigonometric parallax sample of…

KPD0005+5106 is the hottest known helium-rich white dwarf. We have identified NeVIII lines in UV and optical spectra and conclude that it is significantly hotter than previously thought, namely Teff=200,000 K instead of 120,000 K. This is a…

WD J2356$-$209 is a cool metal-polluted white dwarf whose visible spectrum is dominated by a strong and broad sodium feature. Although discovered nearly two decades ago, no detailed and realistic analysis of this star had yet been realized.…

In a search for eclipsing white dwarfs using the Zwicky Transient Facility lightcurves, we identified a deep eclipsing white dwarf with a dark, substellar companion. The lack of an infrared excess and an orbital period of 10 hours made this…

A spectroscopic analysis of the DBA (or DAB) white dwarf KUV 02196+2816 is presented. The observed hydrogen and helium line profiles are shown to be incompatible with model spectra calculated under the assumption of a homogeneous hydrogen…

Hot, compact, hydrogen-deficient pre-white dwarfs (pre-WDs) with effective temperatures of Teff > 70,000 K and a surface gravity of 5.0 < log g < 7.0 are rather rare objects despite recent and ongoing surveys. It is believed that they are…

We studied the class of DB white dwarf stars, using re-calibrated UV spectra for thirty four DBs obtained with the IUE satellite. By comparing the observed energy distributions with model atmospheres, we simultaneously determine…

Spectroscopic observations of white dwarfs reveal that many of them are polluted by exoplanetary material, whose bulk composition can be uniquely probed this way. We present a spectroscopic and photometric analysis of the DA white dwarf…

We report the discovery of a new class of hydrogen-deficient stars: white dwarfs with an atmosphere primarily composed of carbon, with little or no trace of hydrogen or helium. Our analysis shows that the atmospheric parameters found for…

We analyse archival optical data on the binary companion to the millisecond pulsar \j1045\ obtained with the Very Large Telescope. A possible optical counterpart candidate %source position coincides with the pulsar coordinates is found at…

Infrared excesses due to dusty disks have been observed orbiting white dwarfs with effective temperatures between 7200 K and 25000 K, suggesting that the rate of tidal disruption of minor bodies massive enough to create a coherent disk…

We present a near-IR spectroscopic analysis of the intriguing DO white dwarf RE J0503-285. The IR spectrum fails to reveal evidence of the presence of a spatially unresolved, cool, late-type companion. Hence we have placed an approximate…

The majority of merging white dwarfs leave behind a white dwarf remnant. Hot/warm DQ white dwarfs with carbon-rich atmospheres have high masses and unusual kinematics. All evidence points to a merger origin. Here, we demonstrate that far-UV…

We report early FUSE observations of the very hot DA white dwarfs PG1342+444 and REJ0558-371. Detection of photospheric absorption lines allows us to estimate the abundances of C, O, Si, P, S and Fe, the first measurements reported for DA…

EGB6 is an extended, faint old planetary nebula (PN) with an enigmatic nucleus. The central star (PG0950+139) is a hot DAOZ-type white dwarf (WD). An unresolved, compact emission knot was discovered to be located 0.166" away from the WD and…

We present spectroscopic observations confirming the identification of hot white dwarfs among UV-bright sources from the Sandage Two-color Survey of the Galactic plane and listed in the Lanning (Lan) catalog of such sources. A subsample of…

We present analysis of a new pulsating helium-atmosphere (DB) white dwarf, EPIC~228782059, discovered from 55.1~days of {\em K2} photometry. The long duration, high quality light curves reveal 11 independent dipole and quadruple modes, from…

We present spectra for 33 previously unclassified white dwarf systems brighter than V = 17 primarily in the southern hemisphere. Of these new systems, 26 are DA, 4 are DC, 2 are DZ, and 1 is DQ. We suspect three of these systems are…