Related papers: On the white dwarf cooling sequence with extremely…
In the first paper of this series (Blouin et al. 2018), we presented our upgraded cool white dwarf atmosphere code. In this second paper, we use our new models to analyze SDSS J080440.63+223948.6 (J0804+2239), the first DZ star to show…
We present Spitzer 5-15 micron spectroscopy of one cool white dwarf and 3.6-8 micron photometry of 51 cool white dwarfs with T_eff < 6000 K. The majority of our targets have accurate BVRIJHK photometry and trigonometric parallax…
We summarize recent improvements in model atmosphere and internal structure of faint white dwarfs. We derive an analytical cooling theory which illustrates the effects of various physical processes on the energy budget and the cooling…
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…
We present the results of an intensive multiwavelength campaign on nova LMC 2012. This nova evolved very rapidly in all observed wavelengths. The time to fall two magnitudes in the V band was only 2 days. In X-rays the super soft phase…
White dwarfs with metal lines in their spectra act as signposts for post-main sequence planetary systems. Searching the Sloan Digital Sky Survey (SDSS) data release 12, we have identified 231 cool (<9000 K) DZ white dwarfs with strong metal…
Current evolutionary models imply that most Cataclysmic Variables (CVs) have P_orb<2 hours and are Dwarf Nova (DN) systems that are quiescent most of the time. Observations of nearby quiescent DN find that the UV spectrum is dominated by…
Observations of five Y dwarfs with three optical and near-infrared instruments at the 10.4 m Gran Telescopio Canarias are reported. Deep images of the five targets and a low-resolution far-red optical spectrum for one of the targets were…
Deep Hubble Space Telescope (HST) observations with WFPC2 of the nearby globular cluster NGC 6752 have allowed us to obtain accurate photometry for the cluster white dwarfs (WD). A sample of local WDs of known trigonometric parallax and…
White dwarfs are stellar embers depleted of nuclear energy sources that cool over billions of years. These stars, which are supported by electron degeneracy pressure, reach densities of 1e7 grams per cubic centimetre in their cores. It has…
We have exploited the very precise parallaxes, proper motions and photometry of \textit{Gaia}\, Data Release~2 to study white dwarf members of the Hyades star cluster. Gaia photometry and parallaxes for the eight DA white dwarfs confirmed…
The evolution of white dwarfs is essentially a gravothermal process of cooling in which the basic ingredients for predicting their evolution are well identified, although not always well understood. There are two independent ways to test…
WD 1145+017 is currently the only white dwarf known to exhibit periodic transits of planetary debris as well as absorption lines from circumstellar gas. We present the first simultaneous fast optical spectrophotometry and broad-band…
The accurate flux calibration of observational data is vital for astrophysics and cosmology because absolute flux uncertainties of stellar standards propagate into scientific results. With the ever higher precision achieved by telescopic…
We present high resolution Hubble Space Telescope ultraviolet spectroscopy of the dwarf nova EK TrA obtained in deep quiescence. The Space Telescope Imaging Spectrograph data reveal the broad Ly-alpha absorption profile typical of a…
How confident are we that all of the nearest white dwarfs (WDs) have been identified? In an effort to answer this question, we have begun an initiative to identify and characterize new nearby WDs, particularly in the southern hemisphere. We…
Theories of fundamental interactions with large extra dimensions have recently become very popular. Astrophysical bounds from the Sun, red-giants and SN1987a have already been derived by other authors for the theory proposed by…
We present the results of a search for cool white dwarfs in the United Kingdom InfraRed Telescope (UKIRT) Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS). The UKIDSS LAS photometry was paired with the Sloan Digital Sky Survey…
A recent study by Yoon & Langer (2004a) indicated that the inner cores of rapidly accreting (Mdot > 10^{-7} M_sun/yr) CO white dwarfs may rotate differentially, with a shear rate near the threshold value for the onset of the dynamical shear…
We present optical and near-infrared spectroscopy of WISEA J061543.91$-$124726.8, which we rediscovered as a high motion object in the AllWISE survey. The spectra of this object are unusual; while the red optical ($\lambda >$ 7,000 \AA) and…