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We have discovered a detached pair of white dwarfs (WDs) with a 12.75 minute orbital period and a 1315 km s{sup -1} radial velocity amplitude. We measure the full orbital parameters of the systemExpand
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A new class of pulsating white dwarf of extremely low mass: The fourth and fifth members
We report the discovery of two new pulsating extremely low-mass (ELM) white dwarfs (WDs), SDSS J161431.28+191219.4 (hereafter J1614) and SDSS J222859.93+362359.6 (hereafter J2228). Both WDs haveExpand
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Two planets orbiting the recently formed post-common envelope binary NN Serpentis
Planets orbiting post-common envelope binaries provide fundamental information on planet formation and evolution. We searched for such planets in NN Ser ab, an eclipsing short-period binary thatExpand
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SDSS J184037.78+642312.3: The First Pulsating Extremely Low Mass White Dwarf
We report the discovery of the first pulsating extremely low mass (ELM) white dwarf (WD), SDSS J184037.78+642312.3 (hereafter J1840). This DA (hydrogen-atmosphere) WD is by far the coolest and theExpand
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Discovery of pulsations, including possible pressure modes, in two new extremely low mass, He-core white dwarfs
We report the discovery of the second and third pulsating extremely low mass white dwarfs (WDs), SDSS J111215.82+111745.0 (hereafter J1112) and SDSS J151826.68+065813.2 (hereafter J1518). Both haveExpand
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White Dwarf Rotation as a Function of Mass and a Dichotomy of Mode Line Widths: Kepler Observations of 27 Pulsating DA White Dwarfs through K2 Campaign 8
We present photometry and spectroscopy for 27 pulsating hydrogen-atmosphere white dwarfs (DAVs; a.k.a. ZZ Ceti stars) observed by the Kepler space telescope up to K2 Campaign 8, an extensiveExpand
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We report the detection of orbital decay in the 12.75-min, detached binary white dwarf (WD) SDSS J065133.338+284423.37 (hereafter J0651). Our photometric observations over a 13-month baselineExpand
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Core crystallization and pile-up in the cooling sequence of evolving white dwarfs
White dwarfs are stellar embers depleted of nuclear energy sources that cool over billions of years1. These stars, which are supported by electron degeneracy pressure, reach densities of 107 gramsExpand
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Two white dwarfs in ultrashort binaries with detached, eclipsing, likely sub-stellar companions detected by K2
SGP acknowledges the support of the Leverhulme Trust. The research leading to these results has received funding from the European Research Council under the European Union's Seventh FrameworkExpand
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A deep test of radial differential rotation in a helium-atmosphere white dwarf: I. Discovery of pulsations in PG 0112+104
We present the detection of non-radial oscillations in a hot, helium-atmosphere white dwarf using 78.7 d of nearly uninterrupted photometry from the Kepler space telescope. With an effectiveExpand
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