相关论文: The ELM Survey. VII. Orbital Properties of Low Mas…

We present the discovery of 17 low mass white dwarfs (WDs) in short-period P<1 day binaries. Our sample includes four objects with remarkable log(g)~5 surface gravities and orbital solutions that require them to be double degenerate…

We estimate the merger rate of double degenerate binaries containing extremely low mass (ELM) <0.3 Msun white dwarfs in the Galaxy. Such white dwarfs are detectable for timescales of 0.1 Gyr -- 1 Gyr in the ELM Survey; the binaries they…

Extremely low mass (ELM) white dwarfs (WDs) with masses <0.25 Msun are rare objects that result from compact binary evolution. Here, we present a targeted spectroscopic survey of ELM WD candidates selected by color. The survey is 71%…

We analyze radial velocity observations of the 12 extremely low-mass <0.25 Msol white dwarfs (WDs) in the MMT Hypervelocity Star Survey. Eleven of the 12 WDs are binaries with orbital periods shorter than 14 hours; the one non-variable WD…

We present the discovery of 11 new double degenerate systems containing extremely low-mass white dwarfs (ELM WDs). Our radial velocity observations confirm that all of the targets have orbital periods $\leq$ 1 day. We perform spectroscopic…

We present new radial velocity and X-ray observations of extremely low-mass (ELM, 0.2 Msol) white dwarf candidates in the Sloan Digital Sky Survey (SDSS) Data Release 7 area. We identify seven new binary systems with 1-18 h orbital periods.…

We present the discovery of 17 double white dwarf (WD) binaries from our on-going search for extremely low mass (ELM) <0.3 Msun WDs, objects that form from binary evolution. Gaia parallax provides a new means of target selection that we use…

We present Chandra and Swift X-ray observations of four extremely low-mass (ELM) white dwarfs with massive companions. We place stringent limits on X-ray emission from all four systems, indicating that neutron star companions are extremely…

We describe new radial velocity and X-ray observations of extremely low-mass white dwarfs (ELM WDs, ~0.2 Msol) in the Sloan Digital Sky Survey Data Release 4 and the MMT Hypervelocity Star survey. We identify four new short period binaries,…

We present radial velocity observations of four extremely low-mass (0.2 Msol) white dwarfs. All four stars show peak-to-peak radial velocity variations of 540 - 710 km/s with 1.0 - 5.9 hr periods. The optical photometry rules out…

We study a complete, colour-selected sample of double-degenerate binary systems containing extremely low mass (ELM) <0.25 Msol white dwarfs (WDs). We show, for the first time, that Milky Way disk ELM WDs have a merger rate of approximately…

Extremely-low-mass white dwarfs (ELM WDs) with non-degenerate companions are believed to originate from solar-type main-sequence binaries undergoing stable Roche lobe overflow mass transfer when the ELM WD progenitor is at (or just past)…

We present the final sample of 98 detached double white dwarf (WD) binaries found in the Extremely Low Mass (ELM) Survey, a spectroscopic survey targeting <0.3 Msun He-core WDs completed in the Sloan Digital Sky Survey footprint. Over the…

We report the discovery of SDSS~J022932.28+713002.7, a nascent extremely low-mass (ELM) white dwarf (WD) orbiting a massive ($> 1\,M_\odot$ at 2$\sigma$ confidence) companion with a period of 36 hours. We use a combination of spectroscopy,…

We report the discovery of two binary systems, each consisting of a slightly bloated G-type main-sequence star and an unseen companion, identified through photometric data from TESS and radial velocity variation from Gaia. High-resolution…

Double white dwarf binaries are an important remnant of binary evolution as they are possible type Ia supernova progenitors and strong sources of gravitational waves in the low-frequency regime. The double-lined double white dwarf (DBL)…

We present the results from our ongoing spectroscopic survey targeting low mass white dwarf binaries, focusing on the southern sky. We used a Gaia DR2 and eDR3 based selection and identified 28 new binaries, including 19 new extremely low…

Extremely low-mass white dwarfs (ELM WDs) are helium WDs with a mass less than $\sim$$0.3\rm\;M_\odot$. Most ELM WDs are found in double degenerates (DDs) in the ELM Survey led by Brown and Kilic. These systems are supposed to be…

We begin the search for extremely-low mass ($M\leq0.3M_{\odot}$, ELM) white dwarfs (WDs) in the southern sky based on photometry from the VST ATLAS and SkyMapper surveys. We use a similar color-selection method as the Hypervelocity star…

Extremely low-mass white dwarfs (ELM WDs) are helium-core white dwarfs with masses less than 0.3 $M_{\odot}$. Short-period ELM WD binaries that exhibit ellipsoidal variations may harbor heavier companions, either massive white dwarfs or…