相关论文: Infrared Variability of Two Dusty White Dwarfs
A growing sample of white dwarfs (WDs) with metal-enriched atmospheres are accompanied by excess infrared emission, indicating that they are encircled by a compact dusty disk of solid debris. Such `WD debris disks' are thought to originate…
We have compiled photometric data from the Wide-field Infrared Survey Explorer All Sky Survey and other archival sources for the more than 2200 objects in the original McCook & Sion Catalog of Spectroscopically Identified White Dwarfs. We…
The pulsating white dwarf G29-38 possesses a dust disk and metal lines attributed to the accretion of its disk material. \citet{vonhipg29} have reported variability in the equivalent width of G29-38's CaII K line on the timescale of days.…
This letter reports the first detection of a periodic light curve whose modulation is unambiguously due to rotation in a polluted white dwarf. TESS observations of WD 2138-332, at a distance of 16.1 pc, reveal a 0.39 per cent amplitude…
The presence of planetary material in white dwarf atmospheres, thought to be accreted from a dusty debris disc produced via the tidal disruption of a planetesimal, is common. Approximately five per cent of these discs host a co-orbital…
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…
Models of brown dwarf atmospheres suggest they exhibit complex physical behaviour. Observations have shown that they are indeed dynamic, displaying small photometric variations over timescales of hours. Here I report results of infrared…
We present the serendipitous discovery of eclipse-like events around the massive white dwarf SDSS J152934.98+292801.9 (hereafter J1529+2928). We selected J1529+2928 for time-series photometry based on its spectroscopic temperature and…
Near-infrared photometry and spectroscopy is obtained for a heterogeneous sample of nearby white dwarfs with possible excess flux as identified primarily in the Two Micron All Sky Survey. Among the sample of 43 stars are a number of white…
We present high-time-resolution photometry and phase-resolved spectroscopy of the short-period ($P_\mathrm{orb} = 80.52\,\mathrm{min}$) cataclysmic variable SDSS J123813.73-033933.0, observed with the $\mathit{Hubble}$ $\mathit{Space}$…
We have made high precision polarimetric observations of the polluted white dwarf G29-38 with the HIgh Precision Polarimetric Instrument 2. The observations were made at two different observatories -- using the 8.1-m Gemini North Telescope…
25%-50% of all white dwarfs (WDs) host observable and dynamically active remnant planetary systems based on the presence of close-in circumstellar dust and gas and photospheric metal pollution. Currently-accepted theoretical explanations…
White dwarfs (WDs) showing transits from orbiting planetary debris provide significant insights into the structure and dynamics of debris disks. This is a rare class of objects with only eight published systems. In this work, we perform a…
Here we report the detection of dust depletion in a misaligned inner disk around UX Tau A using JWST MIRI spectra. Mid-infrared (MIR) continuum "seesaw" variability was detected in this disk by Spitzer and attributed to variable shadows…
We describe Spitzer images of a sample of dwarf and low surface brightness galaxies, using the high sensitivity and spatial resolution to explore the morphologies of dust in these galaxies. For the starbursting dwarf UGC 10445, we present a…
White dwarfs are routinely observed to have polluted atmospheres, and sometimes significant infrared excesses, that indicate ongoing accretion of circumstellar dust and rocky debris. Typically this debris is assumed to be in the form of a…
We present new observations that densely sample the microwave (4-360 GHz) continuum spectra from eight young systems in the Taurus region. Multi-component, empirical model prescriptions were used to disentangle the contributions from their…
Disks around very low-mass stars (VLMS) provide environments for the formation of Earth-like planets. Mid-infrared observations have revealed that these disks exhibit weak silicate features and strong hydrocarbon emissions. This study…
The MIRI Excess Around Degenerates (MEAD) Survey is a cycle 2 JWST program designed to image nearby white dwarfs with MIRI at 10 and 15 microns. This survey targeted 56 white dwarfs within 25 pc to search for mid-infrared excesses, flux…
We report the discovery of an isolated white dwarf with a spin period of 70 s. We obtained high speed photometry of three ultramassive white dwarfs within 100 pc, and discovered significant variability in one. SDSS J221141.80+113604.4 is a…