Related papers: Pre-Main Sequence Evolutions of Solar Abundance Lo…
We assess the systematic uncertainties in stellar evolutionary calculations for low- to intermediate-mass, main-sequence stars. We compare published stellar tracks from several different evolution codes with our own tracks computed using…
This article presents a study of the evolution of the internal structure and seismic properties expected for low/intermediate mass Pre-Main Sequence (PMS) stars. Seismic and non-seismic properties of PMS stars were analysed. This was done…
Rotation periods are now available for ~500 pre-main sequence and recently arrived main sequence stars of solar-like mass (0.4-1.2 M_sun) in five nearby young clusters: the Orion Nebula Cluster, NGC 2264, alpha Per, IC 2602 and the…
In this review I briefly discuss the theory of pre-main-sequence (PMS) Li depletion in low-mass (0.075<M<1.2 Msun) stars and highlight those uncertain parameters which lead to substantial differences in model predictions. I then summarise…
Previous Hubble Space Telescope (HST) observations of the star-forming cluster NGC 346 in the Small Magellanic Cloud (SMC) had revealed a large population of pre-main sequence (PMS) candidates, characterised by Halpha excess emission in…
We discuss the effects of convective overshooting in the PMS evolution of intermediate mass stars, by analysing in detail the early evolution towards the main sequence of a 2 M_sun stellar model. These effects can be extremely important in…
Young stars on their way to the ZAMS evolve in significantly different ways depending on mass. While the theoretical and observational properties of low- and intermediate-mass stars are rather well understood and/or empirically tested, the…
We discuss the evolutionary properties of primordial massive and very massive stars, supposed to have formed from metal-free gas. Stellar models are presented over a large range of initial masses (8 Msun <= Mi <= 1000 Msun), covering the…
The effects of atomic diffusion on internal and surface abundances of A and F pre-main-sequence stars with mass loss are studied in order to determine at what age the effects materialize, as well as to further understand the processes at…
Formation of massive stars by accretion requires a high accretion rate of > 10^-4 M_sun/yr to overcome the radiation pressure barrier of the forming stars. Here, we study evolution of protostars accreting at such high rates, by solving the…
I have isolated a population of numerous F stars that appear to be pre-main-sequence (PMS). The candidate PMS stars have been identified using CM diagram, reddening, flux excess in the UV and near-infrared, and luminosity anomaly. Negative…
Self-consistent stellar models including all effects of atomic diffusion and radiative accelerations as well as mass loss are evolved from the pre main sequence for stars of 1.35-1.5, M$_{\odot}$ at solar metallicity (Z=0.02). A mass loss…
Recent advancements in stellar evolution modeling offer unprecedented accuracy in predicting the evolution and deaths of stars. We present new stellar evolutionary models computed with the updated PARSEC V2.0 code for a comprehensive and…
We discuss the internal structure of stars in the mass range 1.5 to 4 M_sun from the PMS to the subgiant phase with a particular emphasis on the convective core and the convective superficial layers. Different physical aspects are…
Recently, measurements of abundances in extremely metal poor (EMP) stars have brought new constraints on stellar evolution models. In an attempt to explain the origin of the abundances observed, we computed pre--supernova evolution models,…
We present theoretical predictions for solar-like oscillators in the pre-main sequence phase of stellar evolution. Our pre-main sequence models start from a stellar seed of 0.01 solar masses that gains mass through accretion, offering an…
The key question about early protostellar evolution is how matter is accreted from the large-scale molecular cloud, through the circumstellar disk onto the central star. A sample of 20 Class 0 and I protostars has been observed in continuum…
We summarise recent progress in the understanding of the rotational evolution of low-mass stars (here defined as solar mass down to the hydrogen burning limit) both in terms of observations and modelling. Wide-field imaging surveys on…
Abundance analyses of stars with planets have revealed that their metallicities are enhanced relative to field stars. Such a trend was originally suggested to be due to accretion of iron-rich planetary material. Based on this assumption, we…
We present the results from our time-series imaging data taken with the 1.3m Devasthal fast optical telescope and 0.81m Tenagara telescope in $V$, $R_{c}$, $I_{c}$ bands covering an area of $\sim18^\prime.4\times 18^\prime.4$ towards the…