相关论文: The blue-edge problem of the V1093 Her instability…
We present the results of the first theoretical non-radial non-adiabatic pulsational study of M dwarf stellar models with masses in the range 0.1 to 0.5M_solar. We find the fundamental radial mode to be unstable due to an \epsilon mechanism…
Non-standard modeling of KIC 11145123, a possible blue straggler star, has been asteroseismically carried out based on a scheme to compute stellar models with the chemical compositions in their envelopes arbitrarily modified, mimicking…
Evolutionary tracks and pulsational analysis of models with masses of 13-18 $M_\odot$ are presented. We address two important questions. The first one deals with one of the most unresolved problems in astrophysics, i.e., the existence of a…
[Context.] The hot subdwarf B star HS0702+6043 is known as a large-amplitude, short-period p-mode pulsator of the EC14026 type. Its atmospheric parameters place it at the common boundary between the empirical instability regions of the…
We report on numerical calculations of nonadiabatic eigenvalues and eigenfunctions for g-modes in ZZ Ceti variables. The spectrum of overstable $l=1$ modes delineates the instability strip. Its blue edge occurs where $\omega \tau_c \approx…
Understanding the multi-scale neoclassical and turbulence physics in the edge region (pedestal + scrape-off layer) is required in order to reliably predict performance in future fusion devices. We explore turbulent characteristics in the…
Hot subdwarf B (sdB) stars are evolved, subluminous, helium-burning stars, most likely formed when red-giant stars lose their hydrogen envelope via interactions with close companions. They play an important role in our understanding of…
Pulsational properties of 1.8 M$_{\odot}$ stellar models covering the latest stages of contraction toward the main sequence up to early hydrogen burning phases are investigated by means of linear nonadiabatic analyses. Results confirm that…
A spectroscopic analysis of SDSS J160043.6+074802.9, a binary system containing a pulsating subdwarf-O (sdO) star with a late-type companion, yields Teff = 70 000 +/- 5000 K and log g = 5.25 +/- 0.30, together with a most likely type of K3V…
We use time-evolutions of the linear perturbation equations to study the oscillations of rapidly rotating neutrons stars. Our models account for the buoyancy due to composition gradients and we study, for the first time, the nature of the…
Context. gamma Doradus (gamma Dor) are late A and F-type stars pulsating with high order gravity modes (g-modes). The existence of different evolutionary phases crossing the gamma Dor instability strip raises the question of the existence…
HD 50138 is a B[e] star surrounded by a large amount of circumstellar gas and dust. Its spectrum shows characteristics which may indicate either a pre- or a post-main-sequence system. Mapping the kinematics of the gas in the inner few au of…
A Rayleigh B\'enard instability study using the energy conserving dissipative particle dynamics method is presented here for the first time. The simulation is performed on an ideal dissipative particle dynamics fluid in a three dimensional…
Stellar models with homogeneous abundances fail to reproduce the pulsation frequencies of early B-type stars. Their oscillations are excited by kappa-mechanism involving the Fe-peak elements where they are main contributors to the opacity…
In previous attempts to perform seismic modelling of pulsating subdwarf-B stars, various mode identification techniques are used with uncertain results. We investigated a method so far neglected in sdB stars, but very successful for Main…
High dispersion near-infrared spectra have been taken of seven highly-evolved, variable, intermediate-mass (4-6 Msun) AGB stars in the LMC and SMC in order to look for C, N and O variations that are expected to arise from third dredge-up…
Context: Recent attention has been directed to abundance variations among very young stars. Aims: To perform a detailed abundance study of the Herbig Ae star HD 101412, taking advantage of its unusually sharp spectral lines. Methods:…
We address the origin and evolutionary status of hot subdwarf stars by studying the optical spectral properties of 58 subdwarf O (sdO) stars. Combining them with the results of our previously studied subdwarf B (sdB) stars, we aim at…
Stellar evolution models of B-type stars are still uncertain in terms of internal mixing properties, notably in the area between the convective core and the radiative envelope. This impacts age determination of such stars in addition to the…
The possibility of slow diffusion regions as the origin for extended TeV emission halos around some pulsars (such as PSR J0633+1746 and PSR B0656+14) challenges the standard scaling of the electron diffusion coefficient in the interstellar…