Search for dissertations about: "Stellar nucleosynthesis"

Showing result 1 - 5 of 13 swedish dissertations containing the words Stellar nucleosynthesis.

  2. 1. On the Winds of Carbon Stars and the Origin of Carbon : A Theoretical Study

    Author : Lars Mattsson; Susanne Höfner; Nils Bergvall; Kjell Olofsson; Martin Groenewegen; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; AGB stars; carbon stars; mass loss; stellar winds; circumstellar matter; cosmic dust; stellar evolution; nucleosynthesis; galactic chemical evolution; Astronomy and astrophysics; Astronomi och astrofysik; Astronomy; Astronomi; Fysik; Physics;

    Abstract : Carbon is the basis for life, as we know it, but its origin is still largely unclear. Carbon-rich Asymptotic Giant Branch (AGB) stars (carbon stars) play an important rôle in the cosmic matter cycle and may contribute most of the carbon in the Galaxy. READ MORE

  4. 2. On the Abundances of Li, Be and O in Metal-Poor Stars in the Galaxy

    Author : Ana Elia García Pérez; Martin Asplund; Bengt Gustafsson; Francesca Primas; Beatriz Barbuy; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Astronomy; galactic evolution; stellar abundances; stellar atmospheres; spectral line formation; stellar mixing; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik;

    Abstract : Stellar atmospheres constitute excellent environments to study the chemical evolution of our Galaxy. The chemical composition of these atmospheres reflects the composition of the gas from where these stars were born. READ MORE

  5. 3. On the Chemical Composition of Metal-Poor Stars : Impact of Stellar Granulation and Departures from Local Thermodynamic Equilibrium on the Formation of Spectral Lines

    Author : Remo Collet; Bengt Gustafsson; Martin Asplund; Roger Cayrel; Uppsala universitet; []
    Keywords : Astronomy; late-type stars; stellar abundances; stellar atmospheres; spectral line formation; convection; hydrodynamics; Galactic chemical evolution; Astronomi;

    Abstract : The information about the chemical compositions of stars is encoded in their spectra. Accurate determinations of these compositions are crucial for our understanding of stellar nucleosynthesis and Galactic chemical evolution. READ MORE

  6. 4. Advances in Stellar Astrophysics from Laboratory Spectroscopy

    Author : Stefan Ivarsson; Atomfysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Astronomy; iridium; osmium; uranium; oscillator strengths; Spectroscopy; term analysis; line profiles; line structure; astrophysics; Sun; Chi Lupi; 17 Comae A; chemically peculiar; praseodymium; stars; space research; cosmic chemistry; Astronomi; rymdvetenskap; kosmisk kemi; Fysicumarkivet A:2004:Ivarsson;

    Abstract : Investigation of astrophysical plasmas, such as stellar atmospheres, require both knowledge of atomic structure and data. We present laboratory instruments, techniques and tools for acquisition of the data required to derive important atomic parameters such as, wavelengths, oscillator strengths and line profiles. READ MORE

  7. 5. Modelling the Winds from Carbon Rich AGB Stars : Implications for Stellar Evolution and the Chemical Evolution of Galaxies

    Author : Lars Mattsson; Uppsala universitet; []
    Keywords : ;

    Abstract : Stars on the AGB are known to lose mass at high rates (10-8 - 10-4 Msun/yr) through slow winds (20 km/s), enriching the inter stellar medium with newly synthesised elements. We explore how the mass loss for C-rich AGB stars depends on the basic stellar parameters by computing a large grid of wind models. READ MORE