Related papers: The White Dwarf in EM Cygni: Beyond The Veil
We have analyzed the variability and spectral evolution of the prototype dwarf nova system SS Cygni using RXTE data and AAVSO observations. A series of pointed RXTE/PCA observations allow us to trace the evolution of the X-ray spectrum of…
We analyse the 100pc Gaia white dwarf volume-limited sample by means of VOSA (Virtual Observatory SED Analyser) with the aim of identifying candidates for displaying infrared excesses. Our search focuses on the study of the spectral energy…
A recent cross-correlation between the SDSS DR7 White Dwarf Catalog with the Wide-Field Infrared Survey Explorer ($WISE$) all-sky photometry at 3.4, 4.6, 12, and 22 microns performed by Debes et al. (2011) resulted in the discovery of 52…
We report a Spitzer/IRAC search for infrared excesses around white dwarfs, including 14 newly-observed targets and 16 unpublished archived stars. We find a substantial infrared excess around two warm white dwarfs --- J220934.84+122336.5 and…
FUSE and HST/STIS spectra of the dwarf nova WZ Sge, obtained during and following the early superoutburst of July 2001 over a time span of 20 months, monitor changes in the components of the system during its different phases. The synthetic…
Infrared excess is an important probe of sub-stellar companions and/or debris disks around white dwarfs (WDs). Such systems are still rare for in-depth understanding of their formation and long-term evolution. One of the largest…
Quasi-coherent oscillations have been detected in the extreme ultraviolet flux of the dwarf nova SS Cygni during observations with the Extreme Ultraviolet Explorer satellite of the rise and plateau phases of an anomalous outburst in 1993…
We present time-resolved FUV spectra of the dwarf novae SS Cyg and WX Hyi in quiescence from observations using the Hopkins Ultraviolet Telescope on the Astro-1 and Astro-2 Space Shuttle missions and the Goddard High Resolution Spectrograph…
We describe optical spectroscopic observations of the icy dwarf planet Eris with the 6.5 meter MMT telescope and the Red Channel Spectrograph. We report a correlation, that is at the edge of statistical significance, between blue shift and…
The prototype nova-like variable VY Sculptoris was observed by the IUE during four different optical brightness states of the system. The FUV flux level from the highest state to the lowest state declines by a factor of 28. We have carried…
Short--period ($P<$1 hr orbits) detached double white dwarf binary (DWDB) components identified with transient surveys (e.g. SDSS, ZTF) have hot surface temperatures ($>$10,000 K) and observed radii a factor two larger than completely…
We present synthetic spectra for circumstellar disks that are heated by radiation from a central brown dwarf. Under the assumption of vertical hydrostatic equilibrium, our models yield scaleheights for brown dwarf disks in excess of three…
We present follow-up spectroscopy of 711 white dwarfs within 100 pc, and present a detailed model atmosphere analysis of the 100 pc white dwarf sample in the SDSS footprint. Our spectroscopic follow-up is complete for 83% of the white…
We present a photometric analysis of 19 DA and 13 DAO white dwarfs (WDs) with effective temperatures exceeding 60 kK, building on the spectral analysis reported in the first paper of this two-part study. By examining archival light curves…
Roughly 2% of white dwarfs harbor planetary debris disks detectable via infrared excesses, but only a few percent of these disks show a gaseous component, distinguished by their double-peaked emission at the near-infrared calcium triplet.…
We calculate the stellar evolution of both white dwarfs (WDs) in AM CVn binaries with orbital periods of $P_{\mathrm{orb}} \approx 5-70$ minutes. We focus on the cases where the donor starts as a $M_{\mathrm{He}} < 0.2 \, M_{\odot}$ Helium…
Context: The far-infrared (FIR) and sub-millimeter (submm) emissivity of the Milky Way (MW) cirrus is an important benchmark for dust grain models. Dust masses in other galaxies are generally derived from the FIR/submm using the emission…
A significant fraction of white dwarfs (WDs) host dust/debris disks formed from the tidal disruption of asteroids and planetesimals. Several studies indicate that the disks can attain significant vertical heights through collisional…
AG Dra is a symbiotic variable consisting of a metal poor, yellow giant mass donor under-filling its Roche lobe, and a hot accreting white dwarf, possibly surrounded by an optically thick, bright accretion disk which could be present from…
Optical observations of nova V1974 Cygni (Cygni 1992), spanning a 4 year period, have been used to study its spectroscopic evolution. The data cover a wavelength range from $\sim 3200 - 8000$ \AA and follows the nebular evolutionary phase…