Related papers: The Instability Strip for Pre--Main-Sequence Stars
We present new grids of pre-main sequence (PMS) tracks for stars in the mass range 0.1 to 7.0 Msun. The computations were performed for four different metallicities (Z=0.01, 0.02, 0.03 and 0.04). A fifth table has been computed for the…
The {\delta} Sct stars are a diverse group of intermediate-mass pulsating stars located on and near the main sequence within the classical instability strip in the Hertzsprung-Russell diagram. Many of these stars are hybrid stars pulsating…
We conduct a systematic examination of the properties of models for chemically homogeneous, differentially rotating, main-sequence stars of mass 1-2 M_sun. The models were constructed using a code based on a reformulation of the…
[abridged] We have assembled a database of stars having both masses determined from measured orbital dynamics and sufficient spectral and photometric information for their placement on a theoretical HR diagram. Our sample consists of 115…
Population II pulsatingvariables play a relevant role both as distance indicators and as tracers of the properties of old stellar populations. In this paper we present an update and homogeneous pulsational scenario for a wide range of…
The properties of radial nonlinear pulsations of massive blue stars are computed with the MESA software instrument in its dynamical mode. Pulsational instabilities could be computationally detected and followed if the evolutionary timestep…
Astronomers generally assume planet-forming disks are aligned with the rotation of their host star. However, recent observations have shown evidence of warping in protoplanetary disks. One can measure the statistical alignment between the…
We present the results of a nonadiabatic, linear stability analysis of models of very low-mass stars (VLMSs) and brown dwarfs (BDs) during the deuterium burning phase in the center. We find unstable fundamental modes with periods varying…
Very low-mass stars and brown dwarfs can undergo pulsational instability excited by central deuterium burning during the initial phases of their evolution. We present the results of evolutionary and nonadiabatic linear stability models that…
ZDI studies have shown that the magnetic fields of T Tauri stars can be significantly more complex than a simple dipole and can vary markedly between sources. We collect and summarize the magnetic field topology information obtained to date…
We present proper motion measurements of pre-main sequence (PMS) stars associated with major star-forming regions of the southern hemisphere (Chamaeleon, Lupus, Upper Scorpius - Ophiuchus, Corona Australis), situated in the galactic…
We present a method of determining lower limits on the masses of pre-main-sequence (PMS) stars and so constraining the PMS evolutionary tracks. This method uses the red-shifted absorption feature observed in some emission-line profiles of T…
We analyse public domain time-series photometric observations of 30 known and candidate binary post-AGB stars for measuring pulsation and orbital periods. We derive periodicities for 17 stars for the first time in the literature. Besides…
Major photometric monitoring campaigns of star-forming regions in the past decade have provided rich rotation period distributions of pre-main-sequence stars. The rotation periods span more than an order of magnitude in period, with most…
The evolution of strange mode instabilities into the non linear regime has been followed by numerical simulation for an envelope model of a massive star having solar chemical composition, M=50M_sun, T_eff=10^4K and L=1.17*10^6 L_sun.…
The spectroscopic and photometric analysis of sample Am stars are carried out to determine the stellar characteristics of each studied star. The CCD photometric analysis of HD 98851 and HD 207561 show clear evidence of pulsation variability…
From TESS photometry, 493 mid- to late-B stars with high frequencies (Maia variables) have been identified. The distribution of projected rotational velocities shows that the rotation rates of Maia variables are no different from those of…
Aims. We aim to study chemically peculiar Am and Fm stars, distinguished by their unique abundance patterns, which are crucial for studying mixing processes in intermediate-mass stars. These stars provide a window into the atomic diffusion…
We calculate the evolution of massive stars, which undergo pulsational pair-instability (PPI) when the O-rich core is formed. The evolution from the main-sequence through the onset of PPI is calculated for stars with the initial masses of…
We investigate the pulsational properties of RSG models --- which we evolve from ZAMS masses in the range 10 to $20 \Msun$ --- by means of linear and non-linear calculations. We find period and growth rate of the dominant fundamental mode…