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Related papers: Progress in modeling magnetic white dwarfs

200 papers

AIMS: With our low-resolution spectroscopic observing program for selected blue proper motion stars, we tried to find new white dwarfs (WDs) in the solar neighbourhood. METHODS: We used the LSPM catalogue with a lower proper motion limit of…

Solar and Stellar Astrophysics · Physics 2018-11-07 R. -D. Scholz , H. Meusinger , A. Schwope , H. Jahreiß , I. Pelisoli

In this paper we review the current status of research on the observational and theoretical characteristics of isolated and binary magnetic white dwarfs (MWDs). Magnetic fields of isolated MWDs are observed to lie in the range 10^3-10^9G.…

Solar and Stellar Astrophysics · Physics 2015-06-03 Lilia Ferrario , Domitilla de Martino , Boris Gaensicke

The photospheres of the coolest helium-atmosphere white dwarfs are characterized by fluid-like densities. Under those conditions, standard approximations used in model atmosphere codes are no longer appropriate. Unfortunately, the majority…

Solar and Stellar Astrophysics · Physics 2018-08-29 Simon Blouin , Patrick Dufour , Nicole F. Allard

Using archival Hubble Space Telescope observations, we report the discovery of four variable low-mass white dwarfs ($0.18 \, M_\odot \leq M \leq 0.5 \,M_\odot$) in the globular cluster NGC 6397. One source exhibits a periodic optical…

We present an asteroseismic analysis of the helium atmosphere white dwarf (a DBV) recently found in the field of view of the Kepler satellite. We analyze the 5-mode pulsation spectrum that was produced based on one month of high cadence…

Solar and Stellar Astrophysics · Physics 2015-05-30 Agnés Bischoff-Kim , Roy H. Østensen

We report the discovery of a new magnetic DA white dwarf (WD), WD0011-721, which is located within the very important 20pc volume-limited sample of the closest WDs to the Sun. This star has a mean field modulus <|B|> of 343 kG, and from the…

Solar and Stellar Astrophysics · Physics 2019-08-07 John D. Landstreet , Stefano Bagnulo

We present a study of close white dwarf and M dwarf (WD+dM) binary systems and examine the effect that a close companion has on the magnetic field generation in M dwarfs. We use a base sample of 1602 white dwarf -- main sequence binaries…

Solar and Stellar Astrophysics · Physics 2015-06-05 Dylan P. Morgan , Andrew A. West , Ane Garcés , Silvia Catalán , Saurav Dhital , Miriam Fuchs , Nicole M. Silvestri

This paper summarizes the results of over 17 years of work searching for low mass stellar and substellar companions to more than 370 nearby white dwarfs. Roughly 60 low mass, unevolved companions were found and studied all together, with…

Astrophysics · Physics 2009-11-11 J. Farihi , B. Zuckerman , E. E. Becklin

In this paper, we present corrections to the spectroscopic parameters of DB and DBA white dwarfs with -10.0 < log(H/He) < -2.0, 7.5 < log(g) < 9.0 and 12000 K < T_eff < 34000 K, based on 282 3D atmospheric models calculated with the CO5BOLD…

Solar and Stellar Astrophysics · Physics 2020-11-26 Elena Cukanovaite , Pier-Emmanuel Tremblay , Pierre Bergeron , Bernd Freytag , Hans-Günter Ludwig , Matthias Steffen

We present a new N-body model for the tidal disruption of the Sagittarius (Sgr) dwarf that is capable of simultaneously satisfying the majority of angular position, distance, and radial velocity constraints imposed by current wide-field…

Astrophysics of Galaxies · Physics 2015-05-18 David R. Law , Steven R. Majewski

Despite thousands of spectroscopic detections, only four isolated white dwarfs exhibit Balmer emission lines. The temperature inversion mechanism is a puzzle over 30 years old that has defied conventional explanations. One hypothesis is a…

Solar and Stellar Astrophysics · Physics 2021-03-17 N. Walters , J. Farihi , T. R. Marsh , S. Bagnulo , J. D. Landstreet , J. J. Hermes , N. Achilleos , A. Wallach , M. Hart , C. J. Manser

We present a detailed model atmosphere analysis of massive white dwarfs with $M > 0.9~M_\odot$ and $T_{\rm eff}\geq11,000$ K in the Montreal White Dwarf Database 100 pc sample and the Pan-STARRS footprint. We obtained follow-up optical…

We present detailed evolutionary calculations for carbon - oxygen - and helium - core white dwarf (WD) models with masses ranging from M= 0.1 to M= 1.2 solar masses and for metallicities Z= 0.001 and Z= 0. The sequences cover a wide range…

Astrophysics · Physics 2016-08-30 O. G. Benvenuto , L. G. Althaus

The helium-atmosphere (DB) white dwarfs are commonly thought to be the descendants of the hotter PG1159 stars, which initially have uniform He/C/O atmospheres. In this evolutionary scenario, diffusion builds a pure He surface layer which…

Astrophysics · Physics 2007-05-23 T. S. Metcalfe , R. E. Nather , T. K. Watson , S. -L. Kim , B. -G. Park , G. Handler

We present spectroscopy and photometry of GD 448, a detached white dwarf - M dwarf binary with a period of 2.47h. We find that the NaI 8200A feature is composed of narrow emission lines due to irradiation of the M dwarf by the white dwarf…

Astrophysics · Physics 2015-06-24 P. F. L. Maxted , T. R. Marsh , C. Moran , V. S. Dhillon , R. W. Hilditch

Our simultaneous multicolor (UBVRI) circular polarimetry has revealed nearly sinusoidal variation over the WD spin cycle, and almost symmetric positive and negative polarization excursions. Maximum amplitudes are observed in the B and V…

Astrophysics · Physics 2009-11-13 V. Piirola , T. Vornanen , A. Berdyugin , G. V. Coyne

Accreting magnetic white dwarfs offer an opportunity to understand the interplay between spin-up and spin-down torques in binary systems. Monitoring of the white dwarf spin may reveal whether the white dwarf spin is currently in a state of…

We present results from a search for short time-scale white dwarf variability using \texttt{gPhoton}, a time-tagged database of \textit{GALEX} photon events and associated software package. We conducted a survey of $320$ white dwarf stars…

Spectroscopically identified white dwarfs from the SDSS data release 1 are matched against SDSS data release 1 proper motion survey in the search for common proper motion companions

Solar and Stellar Astrophysics · Physics 2012-04-10 John Greaves

White dwarfs with a F, G or K type companion represent the last common ancestor for a plethora of exotic systems throughout the galaxy, though to this point very few of them have been fully characterised in terms of orbital period and…