Sökning: "late-type stars"
Visar resultat 6 - 10 av 18 avhandlingar innehållade orden late-type stars.
6. Stellar Winds of Cool Giants : Investigating the Mass-Loss Mechanism of AGB Stars
Sammanfattning : Asymptotic giant branch (AGB) stars are luminous cool giants of low to intermediate mass that are strongly pulsating and non-spherical, with heavy mass loss through a stellar wind. The mass loss makes these stars important for galactic chemistry, as the wind enriches the interstellar medium with new elements and dust, and it determines the final fate of these stars. LÄS MER
7. Applications of spectroscopic abundance analysis to late-type stars
Sammanfattning : .... LÄS MER
8. Dynamical atmospheres and winds of M-type AGB stars
Sammanfattning : Mass loss, in the form of slow stellar winds, is a decisive factor for the evolution of cool luminous giants, eventually turning them into white dwarfs. These dense outflows are also a key factor in the enrichment of the interstellar medium with newly produced elements from the interior of these stars. LÄS MER
9. Atomic Processes in Stellar Atmospheres : Inelastic Collisions and Effects on Late-type Spectra
Sammanfattning : Chemical abundances as measured from stellar spectral lines are often subject to uncertainties due to lack of accurate data for inelastic collisions, which is needed for non-local thermodynamic equilibrium (non-LTE) modelling. For cool stars, understanding of collision processes with electrons and hydrogen atoms is required to achieve high precision measurements. LÄS MER
10. Dwarf and Subgiant Stars as Probes of Galactic Chemical and Dynamical Evolution
Sammanfattning : Stellar chemical abundances provide astronomers with vital information about the production of chemical elements. Some stars preserve the composition of the environment in which they were born on their surfaces. LÄS MER