相关论文: Cool white dwarfs : cooling theory and Galactic im…

White dwarfs can be used as galactic chronometers and, therefore, provide important information about galactic evolution if good theoretical models of their cooling are available. Consequently, it is natural to wonder if all the sources or…

White dwarfs are the final remnants of low- and intermediate-mass stars. Their evolution is essentially a cooling process that lasts for $\sim 10$ Gyr. Their observed properties provide information about the history of the Galaxy, its dark…

In this paper we compute detailed evolutionary models providing chemical profiles for white dwarfs having progenitors in the mass range from 1.0 to $7 M_{\sun}$ and we examine the influence of such profiles in the cooling process. The…

The evolution of white dwarfs is a cooling process that depends on the energy stored in the core and on the way in which it is transferred through the envelope. In this paper we show that despite some (erroneous) claims, the redistribution…

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…

A number of so-called ultra-cool white dwarfs have been detected in different surveys so far. However, based on anecdotal evidence it is believed that most or all of these ultra-cool white dwarfs are low-mass products of binary evolution…

White Dwarf luminosities are powerful age indicators, whose calibration should be based on reliable models. We discuss the uncertainty of some chemical and physical parameters and their influence on the age estimated by means of white dwarf…

We present follow-up spectroscopy and a detailed model atmosphere analysis of 29 wide double white dwarfs, including eight systems with a crystallized C/O core member. We use state-of-the-art evolutionary models to constrain the physical…

An accurate assessment of white dwarf cooling times is paramount to place white dwarf cosmochronology of Galactic populations on more solid grounds. This issue is particularly relevant in view of the enhanced observational capabilities…

White dwarfs are stellar embers depleted of nuclear energy sources that cool over billions of years. These stars, which are supported by electron degeneracy pressure, reach densities of 1e7 grams per cubic centimetre in their cores. It has…

Within the theoretical framework of some modern unification theories the constants of nature are functions of cosmological time. White dwarfs offer the possibility of testing a possible variation of G and, thus, to place constraints to…

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 and density…

The evolution of white dwarfs is a simple gravothermal process. This means that their luminosity function, i.e. the number of white dwarfs per unit bolometric magnitude and unit volume as a function of bolometric magnitude, is a…

The evolution of white dwarfs is essentially a cooling process that depends primarily on the energy stored in their degenerate cores and on the transparency of their envelopes. In this paper we compute accurate cooling sequences for…

We present full evolutionary calculations appropriate for the study of hydrogen-rich DA white dwarfs. This is done by evolving white dwarf progenitors from the zero age main sequence, through the core hydrogen burning phase, the helium…

The continuous cooling of a white dwarf is punctuated by events that affect its cooling rate. Probably the most significant of those is the crystallization of its core, a phase transition that occurs once the C/O interior has cooled down…

We present new white dwarf cooling models which incorporate an accurate outer boundary condition based on new opacity and detailed radiative transfer calculations. We find that helium atmosphere dwarfs cool considerably faster than has…

White dwarfs are almost completely degenerate objects that cannot obtain energy from thermonuclear sources, so their evolution is just a gravothermal cooling process. Recent improvements in the accuracy and precision of the luminosity…

We study the effects of massive scalar-tensor theories on the internal properties, crystallization, and cooling process of white dwarf stars that might potentially solve observational tensions. We show that these modified gravity theories…

White dwarfs which exhibit transit signatures of planetary debris and accreted planetary material provide exceptional opportunities to probe the material composition and dynamical structure of planetary systems. Although previous…