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相关论文: New evolutionary sequences for hot H-deficient whi…

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We present deep photometric observations of the open cluster NGC 2477 using HST/WFPC2. By identifying seven cluster white dwarf candidates, we present an analysis of the white dwarf age of this cluster, using both the traditional method of…

太阳与恒星天体物理 · 物理学 2016-02-19 Elizabeth J. Jeffery , Ted von Hippel , Steven DeGennaro , David van Dyk , Nathan Stein , William H. Jefferys

Cool white dwarfs are reliable and independent stellar chronometers. The most common white dwarfs have carbon-oxygen dense cores. Consequently, the cooling ages of very cool white dwarfs sensitively depend on the adopted phase diagram of…

太阳与恒星天体物理 · 物理学 2015-05-30 Leandro G. Althaus , Enrique García-Berro , Jordi Isern , Alejandro H. Córsico , Marcelo M. Miller Bertolami

Splaver and coworkers have measured the masses of the white dwarf and the neutron star components of the PSR J1713+0747 binary system pair by Shapiro Delay. We attempt to find the original configuration of this system performing a set of…

天体物理学 · 物理学 2009-06-16 O. G. Benvenuto , R. D. Rohrmann , M. A. De Vito

We have presented 309 new white-dwarf (WD) + main-sequence (MS) star binaries identified from the Sloan Digital Sky Survey (SDSS) Tenth Data Release (DR10). The majority of them consist of a white dwarf and a low-mass secondary (typically M…

太阳与恒星天体物理 · 物理学 2015-06-23 Lifang Li , Xiaobo Gong , Fenghui Zhang , Quanwang Han , Xiaoyang Kong

A sequence of pure-hydrogen CO5BOLD 3D model atmospheres of DA white dwarfs is presented for a surface gravity of log g = 8 and effective temperatures from 6000 to 13,000 K. We show that convective properties, such as flow velocities,…

太阳与恒星天体物理 · 物理学 2015-06-15 P. -E. Tremblay , H. -G. Ludwig , M. Steffen , B. Freytag

We present the discovery of the first T dwarf + white dwarf binary system LSPM 1459+0857AB, confirmed through common proper motion and spectroscopy. The white dwarf is a high proper motion object from the LSPM catalogue that we confirm…

TOI-1259 consists of a transiting exoplanet orbiting a main sequence star, with a bound outer white dwarf companion. Less than a dozen systems with this architecture are known. We conduct follow-up spectroscopy on the white dwarf TOI-1259B…

Hydrogen-rich matter has been added to a CO white dwarf of initial mass 0.516 \msun at the rates $10^{-8}$ and $2\times 10^{-8}$ \msun \yrm1, and results are compared with those for a white dwarf of the same initial mass which accretes pure…

天体物理学 · 物理学 2009-10-31 L. Piersanti , S. Cassisi , I. Iben , A. Tornambe'

The hydrogen-deficiency in extremely hot post-AGB stars of spectral class PG1159 is probably caused by a (very) late helium-shell flash or a AGB final thermal pulse that consumes the hydrogen envelope, exposing the usually-hidden intershell…

天体物理学 · 物理学 2007-10-25 K. Werner , T. Rauch , E. Reiff , J. W. Kruk

The prediction of the spins of the compact remnants is a fundamental goal of the theory of stellar evolution. Here, we confront the predictions for white dwarf spins from evolutionary models including rotation with observational…

天体物理学 · 物理学 2009-11-13 M. P. L. Suijs , N. Langer , A. -J. Poelarends , S. -C. Yoon , A. Heger , F. Herwig

We present new cooling models for carbon-oxygen white dwarfs with both H- and He-atmospheres, covering the whole relevant mass range, to extend our updated BaSTI (a Bag of Stellar Tracks and Isochrones) stellar evolution archive. They have…

太阳与恒星天体物理 · 物理学 2021-12-22 Maurizio Salaris , Santi Cassisi , Adriano Pietrinferni , Sebastian Hidalgo

We investigate the effects of element diffusion on the structure and evolution of low-mass helium white dwarfs (WD). Attention is focused on the occurrence of hydrogen shell flashes induced by diffusion processes during cooling phases.…

天体物理学 · 物理学 2009-10-31 L. G. Althaus , A. M. Serenelli , O. G. Benvenuto

Recent Hubble Space Telescope observations have unveiled the white dwarf cooling sequence of the Galactic bulge. Although the degenerate sequence can be well fitted employing the most up-to-date theoretical cooling sequences, observations…

星系天体物理 · 物理学 2018-02-21 S. Torres , E. García-Berro , R. Cojocaru , A. Calamida

Some white dwarfs undergo significant changes in atmospheric composition owing to the diffusion and mixing of residual hydrogen in a helium-rich envelope. Of particular interest are a few objects exhibiting hydrogen and helium line…

太阳与恒星天体物理 · 物理学 2025-01-28 Antoine Bédard , Pier-Emmanuel Tremblay

White dwarf (WD) stars evolve simply and predictably, making them reliable age indicators. However, self-consistent validation of the methods for determining WD total ages has yet to be widely performed. This work uses 1565 wide ( > 100 au)…

太阳与恒星天体物理 · 物理学 2022-08-17 Tyler M. Heintz , J. J. Hermes , Kareem El-Badry , Charlie Walsh , Jennifer L. van Saders , C. E. Fields , Detlev Koester

There is a striking paucity of hydrogen-rich (DA) white dwarfs (WDs) relative to their hydrogen-deficient (non-DA) counterparts at the very hot end of the WD cooling sequence. The three hottest known DAs (surface gravity log g $\geq$ 7.0)…

太阳与恒星天体物理 · 物理学 2018-12-26 K. Werner , T. Rauch , N. Reindl

We present a homogeneous analysis of 1023 DBZ/DZ(A) and 319 DQ white dwarf stars taken from the Montreal White Dwarf Database. This represents a significant increase over the previous comprehensive studies on these types of objects. We use…

太阳与恒星天体物理 · 物理学 2020-01-08 S. Coutu , P. Dufour , P. Bergeron , S. Blouin , E. Loranger , N. F. Allard , B. H Dunlap

The planet-hosting and Sirius-type binary system epsilon Reticulum (HD 27442) is examined from the perspective of its more evolved white dwarf secondary. The stellar parameters are determined from a combination of Balmer line spectroscopy,…

太阳与恒星天体物理 · 物理学 2012-06-06 J. Farihi , M. R. Burleigh , J. B. Holberg , S. L. Casewell , M. A. Barstow

We present an evolutionary sequence of a low mass star from the Asymptotic Giant Branch (AGB) through its post-AGB stage, during which its surface chemical composition changes from hydrogen-rich to strongly hydrogen-deficient as consequence…

天体物理学 · 物理学 2007-05-23 F. Herwig , T. Bloecker , N. Langer , T. Driebe

Common envelope (CE) evolution, which is crucial in creating short period binaries and associated astrophysical events, can be constrained by reverse modeling of such binaries' formation histories. Through analysis of a sample of…

太阳与恒星天体物理 · 物理学 2022-12-20 Peter Scherbak , Jim Fuller