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相关论文: The mode trapping properties of full DA white dwar…

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We present new cooling sequences, color-magnitude diagrams, and color-color diagrams for cool white dwarfs with pure hydrogen atmospheres down to an effective temperature $\te=1500$ K. We include a more detailed treatment of the physics of…

天体物理学 · 物理学 2009-10-31 Gilles Chabrier , Pierre Brassard , Gilles Fontaine , Didier Saumon

We consider the pulsational properties of white dwarf star models with temperatures appropriate for the ZZ Ceti instability strip and with masses large enough that they should be substantially crystallized. Our work is motivated by the…

天体物理学 · 物理学 2009-10-31 M. H. Montgomery , D. E. Winget

Numerous experimental data on the rapid solidification of binary systems exhibit the formation of metastable solid phases with the initial (nominal) chemical composition. This fact is explained by complete solute trapping leading to…

材料科学 · 物理学 2009-11-13 Peter Galenko

The possible existence of warm ($T_{\rm eff}\sim19\,000$ K) pulsating DA white dwarf (WD) stars, hotter than ZZ Ceti stars, was predicted in theoretical studies more than 30 yr ago. However, to date, no pulsating warm DA WD has been…

We reexamine the theoretical instability domain of pulsating DB white dwarfs (DBV or V777 Her variables). We performed an extensive $g$-mode nonadiabatic pulsation analysis of DB evolutionary models considering a wide range of stellar…

天体物理学 · 物理学 2016-08-14 A. H. Córsico , L. G. Althaus , M. M. Miller Bertolami , E. García-Berro

Rapidly rotating late M dwarfs are observed in two different branches of magnetic activity, although they operate in the same stellar parameter range. Current empirical evidence indicates that M dwarfs with spectral types ranging from M3 /…

太阳与恒星天体物理 · 物理学 2025-11-18 Giuseppina Nigro , Francesco Berrilli , Giuseppe Bono , Dario Del Moro , Luca Giovannelli , Valentina Penza , Raffaele Reda

Recent advances in time-domain astronomy have uncovered a new class of optical transients with timescales shorter than typical supernovae and a wide range of peak luminosities. Several subtypes have been identified within this broad class,…

高能天体物理现象 · 物理学 2017-05-31 Enrique García-Berro , Carles Badenes , Gabriela Aznar-Siguán , Pablo Lorén-Aguilar

As dense and hot bodies with a well-understood equation of state, white dwarfs offer a unique opportunity to investigate new physics. In this paper, we examine the role of dark sectors, which are extensions of the Standard Model of particle…

高能物理 - 唯象学 · 物理学 2023-08-31 Jaime Hoefken Zink , Maura E. Ramirez-Quezada

Advective trapping occurs when solute enters low velocity zones in heterogeneous porous media. Classical local modeling approaches combine the impact of slow advection and diffusion into a hydrodynamic dispersion coefficient and many…

流体动力学 · 物理学 2020-12-02 Juan J. Hidalgo , Insa Neuweiler , Marco Dentz

One of the least understood aspects of white dwarf evolution is the process by which they are formed. We are aided, however, by the fact that many H- and He-deficient pre-white dwarfs (PWDs) are multiperiodic g-mode pulsators. Pulsations in…

天体物理学 · 物理学 2009-10-31 M. Sean O'Brien

We present a study of the iron abundance pattern in hot hydrogen-rich (DA) white dwarfs. The study is based on new and archival far ultraviolet spectroscopy of a sample of white dwarfs in the temperature range 30,000 K < T_eff < 64,000 K.…

天体物理学 · 物理学 2008-11-26 Stephane Vennes , Pierre Chayer , Jean Dupuis , Thierry Lanz

Diffusion coefficients are essential microphysics input for modeling white dwarf evolution, as they impact phase separation at crystallization and sedimentary heat sources. Present schemes for computing diffusion coefficients are accurate…

太阳与恒星天体物理 · 物理学 2022-04-06 M. E. Caplan , E. B. Bauer , I. F. Freeman

A non negligible fraction of white dwarf stars show the presence of heavy elements in their atmospheres. The most accepted explanation for this contamination is the accretion of material coming from tidally disrupted planetesimals, which…

太阳与恒星天体物理 · 物理学 2022-04-13 F. C. Wachlin , G. Vauclair , S. Vauclair , L. G. Althaus

The ability to control the laser modes within a subwavelength resonator is of key relevance in modern optoelectronics. This work deals with the theoretical research on optical properties of a PT--symmetric nano--scaled dimer formed by two…

光学 · 物理学 2021-04-07 Mauro Cuevas , Mojtaba Karimi , Carlos J Zapata-Ropdriguez

We present a new, better-constrained asteroseismic analysis of the helium-atmosphere (DB) white dwarf discovered in the field of view of the original Kepler mission. Observations obtained over the course of two years yield at least seven…

太阳与恒星天体物理 · 物理学 2014-08-21 Agnes Kim , Roy Ostensen , J. J. Hermes , Judith Provencal

The white dwarf luminosity function is well understood in terms of standard model physics and leaves little room for exotic cooling mechanisms related to the possible existence of new weakly interacting light particles. This puts…

高能物理 - 唯象学 · 物理学 2015-06-17 Lorenzo Ubaldi

We analyze the stability of g-modes in variable white dwarfs with hydrogen envelopes. In these stars, the radiative layer contributes to mode damping because its opacity decreases upon compression and the amplitude of the Lagrangian…

天体物理学 · 物理学 2009-10-08 Peter Goldreich , Yanqin Wu

Some hot DA white dwarfs have circumstellar high ion absorption features in their spectra, in addition to those originating in the photosphere. In many cases, the line profiles of these absorbing components are unresolved. Given the…

太阳与恒星天体物理 · 物理学 2015-06-11 Nathan J. Dickinson , Martin A. Barstow , Barry Y. Welsh

A detailed analysis of the very cool white dwarfs SDSS 1337+00 and LHS 3250 is presented. Model atmosphere calculations with improved collision-induced absorptions by molecular hydrogen indicate that a pure hydrogen composition can be ruled…

天体物理学 · 物理学 2008-11-26 P. Bergeron , S. K. Leggett

We reveal peculiarities of the trapped (dark) mode excitation in a polarization-insensitive all-dielectric metasurface, whose unit super-cell is constructed by particularly arranging four cylindrical dielectric particles. Involving…