相关论文: Combining observational techniques to constrain co…
Red supergiants (RSGs) are an evolved He-burning phase in the lifetimes of moderately high mass (10 - 25 solar mass) stars. The physical properties of these stars mark them as an important and extreme stage of massive stellar evolution, but…
Most current models of low mass red giant stars do not reproduce the observed position of the red giant branch luminosity bump, a diagnostic of the maximum extent of the convective envelope during the first dredge up. Global asteroseismic…
The distribution of stars in the Hertzsprung Russell diagram (HRD) for a stellar conglomeration represents a snapshot of its evolving stellar population. Some of the supergiant stars may transit the HRD from blue to red and then again to…
Despite major progress in our understanding of massive stars, concerning discrepancies still remain between observations and theory. Most notable are the numerous stars observed beyond the theoretical main sequence, an evolutionary phase…
Massive stars in the Hertzsprung gap are a mixed population of objects in short-lived evolutionary phases: yellow supergiants (YSGs) evolving towards the red supergiant (RSG) phase, partially-stripped post-RSGs, and other, rarer outcomes of…
The post main-sequence evolution of massive stars is very sensitive to many parameters of the stellar models. Key parameters are the mixing processes, the metallicity, the mass-loss rate and the effect of a close companion. We study how the…
Red supergiants (RSGs) are an evolved stage in the life of intermediate massive stars (than than 25 solar masses). For many years, their location in the H-R diagram was at variance with the evolutionary models. Using the MARCS stellar…
We provide an observational view of evolutionary models in the Hertzsprung--Russell diagram, on the main sequence. For that we computed evolutionary models with the code STAREVOL for 15 < M/Msun < 100. We subsequently calculated atmosphere…
Massive stars are key contributors to the chemodynamical evolution of galaxies and the Universe. Despite their significance, discrepancies between observational data and theoretical models of massive stars challenge our understanding of…
Stellar evolution models calculate convective boundaries using either the Schwarzschild or Ledoux criterion, but confusion remains regarding which criterion to use. Here we present a 3D hydrodynamical simulation of a convection zone and…
Red supergiants (RSGs) are an evolved stage in the life of intermediate massive stars (<25Mo). For many years their location in the H-R diagram was at variance with the evolutionary models. Using the MARCS stellar atmosphere models, we have…
The evolution of massive stars is affected by a variety of physical processes including convection, rotation, mass loss and binary interaction. Because these processes modify the internal chemical abundance profiles in multiple ways…
Convection is ubiquitous in stars and occurs under many different conditions. Here we explore convection in main-sequence stars through two lenses: dimensionless parameters arising from stellar structure and parameters which emerge from the…
Red supergiants (RSGs) are a He-burning phase in the evolution of moderately massive stars (10-25 solar masses). For many years, the assumed physical properties of these stars placed them at odds with the predictions of evolutionary theory.…
Red supergiant stars (RSGs) represent the final evolutionary phase of the majority of massive stars and hold a unique role in testing the physics of stellar models. Eighty eight RSGs in the Small Magellanic Cloud (SMC) were recently found…
The circumstellar medium around massive stars is strongly impacted by stellar winds, radiation, and explosions. We use numerical simulations of these interactions to constrain the current properties and evolutionary history of various stars…
We compute full evolutionary sequences of red giant branch stars close to the luminosity bump by including state of the art composition transport prescriptions for the thermohaline mixing regimes. In particular we adopt a self-consistent…
Current massive star evolution grids are not able to simultaneously reproduce the empirical upper luminosity limit of red supergiants, the Humphrey-Davidson (HD) limit at high and low metallicity. In this study, we provide a better…
Convection plays a key role in the evolution of stars due to energy transport and mixing of composition. Despite its importance, this process is still not well understood. One longstanding conundrum in all 1D stellar evolution codes is the…
Mass loss is one of the key parameters that determine stellar evolution. Despite the progress we have achieved over the last decades we still cannot match the observational derived values with theoretical predictions. Even worse, there are…