• The Gaia white dwarf population within 100 pc of the Sun 

      Torres, S.; Rebassa-Mansergas, A.; Jiménez-Esteban, F.M.; Cantero, C.; Canals, P.; Skorobogatov, G.; Solano, E. (2018-07)
      The recent Gaia Data Release 2 has provided an unprecedented sample of the local white dwarf population. The high astrometric resolution and the photometry provided by Gaia allows to build a clean magnitude-color diagram ...
    • Revisiting the White Dwarf Luminosity Function from the Palomar-Green Survey 

      Bédard, A.; Bergeron, P.; Fontaine, G. (2018-07)
      We present updated atmospheric parameters for all DA, DB, and DO white dwarfs in the complete sample of the Palomar-Green survey. In particular, we perform a spectroscopic analysis of the DO stars using our new set of ...
    • A New Look at Magnetic White Dwarfs 

      Hardy, F.; Dufour, P.; Jordan, S. (2018-07)
      We present a homogeneous photometric analysis of a large sample of magnetic DA white dwarfs as well as selected results from a spectrophotometric analysis of magnetic carbon-dominated atmosphere white dwarfs. We find ...
    • Evolution and Asteroseismology of Pulsating Low-Mass White Dwarfs 

      Calcaferro, L.M.; Corsico, A.H.; Althaus, L.G.; Romero, A.D.; Kepler, S.O. (2018-07)
      Many low-mass white dwarfs are being discovered in the field of our galaxy and some of them exhibit g-mode pulsations, comprising the extremely low-mass variable (ELMV) stars class. Although it is generally believed ...
    • Blue Large-Amplitude Pulsators (BLAPs): Possible Origin, Evolutionary Status, and Nature of their Pulsations 

      Corsico, A.H.; Romero, A.D.; Althaus, L.G.; Pelisoli, I.; Kepler, S.O. (2018-07)
      The Blue Large-Amplitude Pulsators (BLAPs) constitute a new class of pulsating stars. They are hot stars with effective temperatures of Teff ~ 30000 K and surface gravities of log g ~ 4.9, that pulsate with periods ...
    • Asteroseismological Study on PG 0112+104 with Pure and Screened Coulomb Potential 

      Chen, Y.H. (2018-07)
      With 78.7 days of observations by Kepler space telescope, Hermes et al. (2017) made a detailed mode identification on a hot DBV star PG 0112+104. In total, 11 likely m = 0 components with 5 triplets and 3 quintuplets ...
    • Evolutionary and Pulsational Properties of Ultra-massive White Dwarfs. The Role of Oxygen-Neon Phase Separation. 

      De Geronimo, F.C.; Camisassa, M.E.; Corsico, A.H.; Althaus, L.G. (2018-07)
      Ultra-massive hydrogen-rich white dwarf stars are expected to harbour oxygen/neon cores resulting from semidegenerate carbon burning when the progenitor star evolves through the super asymptotic giant branch (S-AGB) ...
    • An Update on Pulsations in Accreting White Dwarfs 

      Szkody, Paula; Mukadam, Anjum (2018-07)
      Since the last white dwarf workshop, there is continuing evidence that long (hrs to days) periodicities are being found in white dwarfs that are undergoing accretion in close binary systems. Pulsation modes remain a ...
    • Evolutionary and pulsational properties of ultra-massive white dwarfs. The role of oxygen-neon phase separation. 

      De Gerónimo, F.C.; Camisassa, M.E.; Córsico, A.H.; Althaus, L.G. (2018-07)
      Ultra-massive hydrogen-rich white dwarfs (WDs) are expected to harbor oxygen/neon cores resulting from semi-degenerate carbon burning when the progenitor star evolves through the super asymptotic giant branch (SAGB) ...
    • An Analysis of the Circumstellar Absorption of WD 1145+017 

      Fortin-Archambault, M.; Dufour, P.; Xu, S. (2018-07)
      WD 1145+017 is a white dwarf that has an actively disintegrating object in orbit and also uniquely displays circumstellar gas absorption. We present a preliminary analysis of the circumstellar absorption features present ...
    • The difficulty of finding double-degenerate progenitors of type Ia supernovae 

      Rebassa-Manserga, A.; Toonen, S.; Korol, V.; Torres, S. (2018-07)
      The double-degenerate progenitors of type Ia supernovae (SNIa) are double white dwarf binaries with a total mass near the Chandrasekhar limit and with merger timescales smaller than the Hubble time. The fact that we ...
    • Temperatures and Chemical Abundances of Accreting White Dwarfs in Cataclysmic Binaries 

      Sion, E.M.; Godon, P. (2018-07)
      We present new results on surface temperatures, and chemical abundances of accreting white dwarfs (WD) in cataclysmic and symbiotic binaries. The S-Type symbiotic system RW Hydrae contains an accreting WD with a surface ...
    • Numerical simulations of the convective dilution process in helium-rich white dwarfs 

      Rolland, B.; Bergeron, P.; Fontaine, G. (2018-07)
      DB and DBA white dwarfs are generally believed to be the result of a process by which a thin radiative hydrogen atmosphere floating in diffusive equilibrium on top of a helium envelope is eventually completely diluted ...
    • Luminosity and cooling suppression in magnetized white dwarfs 

      Bhattacharya, M.; Mukhopadhyay, B.; Mukerjee, S. (2018-07)
      We investigate the luminosity and cooling of highly magnetized white dwarfs where cooling occurs by the diffusion of photons. We solve the magnetostatic equilibrium and photon diffusion equations to obtain the temperature ...
    • Constraining the Milky Way potential with Double White Dwarfs 

      Korol, V.; Rossi, E.M.; Barausse, E. (2018-07)
      The upcoming LISA mission is the only experiment that will allow us to study the Milky Way’s structure using gravitational wave signals from Galactic double white dwarfs (DWDs). The total number of expected detections ...
    • 25 years of using the spectroscopic method: where do we stand? 

      Bergeron, P.; Genest-Beaulieu, C.; Coutu, S.; Blouin, S.; Bédard, A.; Cloutier, S. (2018-07)
      The spectroscopic technique, which consists in fitting high signal-to-noise optical spectra with the predictions of state-of-the-art model atmospheres, has routinely been used for over 25 years to measure the ...
    • Mg line profiles for cool WD and their application in the UV 

      Gadéa, F.X.; Leininger, T.; Guillon, G.; Allard, N.F.; Blouin, S.; Dufour, P. (2018-07)
      Since last decade there have been great advances and extremely exciting results in the search and interpretation for cool DZ white dwarfs. In the formation of their spectra, the far wings of alkaline earth metals like ...
    • White dwarf collisions and the meteoritic Ne-E anomaly 

      Isern, J.; Bravo, E. (2018-07)
      The analysis of noble gases in primitive meteorites has shown the existence of anomalous isotopic abundances when compared with the average Solar System values. In particular it has been found that some graphite grains ...
    • Improved and Tested: A New Generation of Cool White Dwarf Atmosphere Models 

      Blouin, S.; Dufour, P.; Allard, N.F.; Kilic, M. (2018-07)
      The photosphere of cool, helium-rich white dwarfs is notoriously tricky to model due to its fluid-like density. Using modern ab initio calculations, we have developed a new generation of atmosphere models that include ...
    • The gravitational redshift of Sirius B 

      Joyce, S.R.G.; Barstow, M.A.; Holberg, J.B.; Bond, H.E.; Casewell, S.L.; Burleigh, M.R. (2018-07)
      Previous measurements of the gravitational redshift of Sirius B have resulted in a mass estimate which is significantly larger than the mass measured from the binary orbit. We have obtained new HST observations of ...