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Two New Tidally Distorted White Dwarfs

Hermes, J. J.; Kilic, Mukremin; Brown, Warren R.; Montgomery, Michael H.; Winget, D. E. (2012-04)

We identify two new tidally distorted white dwarfs (WDs), SDSS J174140.49+652638.7 and J211921.96-001825.8 (hereafter J1741 and J2119). Both stars are extremely low mass (ELM, <= 0.2 M-circle dot)WDs in short-period, ...

Discovery Of Pulsations, Including Possible Pressure Modes, In Two New Extremely Low Mass, He-Core White Dwarfs

Hermes, J. J.; Montgomery, Michael H.; Winget, D. E.; Brown, Warren R.; Gianninas, A.; Kilic, Mukremin; Kenyon, S. J.; Bell, Keaton J.; Harrold, Samuel T. (2013-03)

We report the discovery of the second and third pulsating extremely low mass (ELM) white dwarfs (WDs), SDSS J111215.82+111745.0 (hereafter J1112) and SDSS J151826.68+065813.2 (hereafter J1518). Both have masses < 0.25 ...

Radius Constraints From High-Speed Photometry Of 20 Low-Mass White Dwarf Binaries

Hermes, J. J.; Brown, Warren R.; Kilic, Mukremin; Gianninas, A.; Chote, Paul; Sullivan, Denis J.; Winget, D. E.; Bell, Keaton J.; Falcon, Ross E.; Winget, K. I.; Mason, Paul A.; Harrold, Samuel T.; Montgomery, Michael H. (2014-09)

We carry out high-speed photometry on 20 of the shortest-period, detached white dwarf binaries known and discover systems with eclipses, ellipsoidal variations (due to tidal deformations of the visible white dwarf), and ...

Discovery of an Ultramassive Pulsating White Dwarf

Hermes, J. J.; Kepler, S. O.; Castanheira, Barbara G.; Gianninas, A.; Winget, D. E.; Montgomery, M. H.; Brown, Warren R.; Harrold, Samuel T. (2013-07)

We announce the discovery of the most massive pulsating hydrogen-atmosphere white dwarf (WD) ever discovered, GD 518. Model atmosphere fits to the optical spectrum of this star show it is a 12,030 +/- 210 K WD with a log ...

Rapid Orbital Decay in the 12.75-Minute Binary White Dwarf J0651+2844

Hermes, J. J.; Kilic, Mukremin; Brown, Warren R.; Winget, D. E.; Prieto, Carlos Allende; Gianninas, A.; Mukadam, Anjum S.; Cabrera-Lavers, Antonio; Kenyon, Scott J. (2012-10)

We report the detection of orbital decay in the 12.75-minute, detached binary white dwarf (WD) SDSS J065133.338+284423.37 (hereafter J0651). Our photometric observations over a 13 month baseline constrain the orbital period ...

A 12 Minute Orbital Period Detached White Dwarf Eclipsing Binary

Brown, Warren R.; Kilic, Mukremin; Hermes, J. J.; Prieto, Carlos Allende; Kenyon, Scott J.; Winget, D. E. (2011-08)

We have discovered a detached pair of white dwarfs (WDs) with a 12.75 minute orbital period and a 1315 km s(-1) radial velocity amplitude. We measure the full orbital parameters of the system using its light curve, which ...

A Dark Spot On A Massive White Dwarf

Kilic, Mukremin; Gianninas, Alexandros; Bell, Keaton J.; Curd, Brandon; Brown, Warren R.; Hermes, J. J.; Dufour, P.; Wisniewski, J. Patrick; Winget, D. E.; Winget, K. I. (2015-12)

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 ...

SDSS J184037.78+642312.3: the First Pulsating Extremely Low Mass White Dwarf

Hermes, J. J.; Montgomery, M. H.; Winget, D. E.; Brown, Warren R.; Kilic, Mukremin; Kenyon, Scott J. (2012-05)

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 the lowest-mass pulsating WD, ...