Sökning: "stellar mixing"

Visar resultat 1 - 5 av 8 avhandlingar innehållade orden stellar mixing.

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

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

    Sammanfattning : 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. LÄS MER

  3. 2. Observations of rare supernovae and their environments

    Författare :Francesco Taddia; Jesper Sollerman; Maryam Modjaz; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Supernova; stellar evolution; metallicity; circumstellar interaction; Astronomy; astronomi;

    Sammanfattning : Supernovae (SNe) are the final stage in the life of massive stars. Their explosion unbinds the progenitor star revealing its inner layers. The SN ejecta interact with the circumstellar material (CSM), providing further information on the progenitor star. LÄS MER

  4. 3. The origin and chemical evolution of iron-peak and neutron-capture elements in the Milky Way disk

    Författare :Chiara Battistini; Astronomi - Genomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Stars: abundances; Stars: solar-type; Galaxy: disk; Galaxy: evolution; Galaxy: solar neighbourhood;

    Sammanfattning : All the elements heavier than Li are created during stellar evolution. Even if our knowledge of this process is good, many questions still remain. LÄS MER

  5. 4. G och K stjärnors effektiva temperaturer och deras kol-, kväve- och syrehalter

    Författare :Urban Olof Frisk; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : This study is aimed at increasing our knowledge and understanding of the evolutionary stages during and after the main sequence phase. The study is based on new photometric and spectroscopic observations of stars in the region from the main sequence and up to the red giants. LÄS MER

  7. 5. The nature of kinematic structures in the Galactic disc

    Författare :Iryna Kushniruk; Astronomi - Genomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Galaxy : evolution; Galaxy: structure; Galaxy : kinematics and dynamics;

    Sammanfattning : The velocity distribution of stars in the Galactic disc is complex and consists of a vast number of kinematic structures, that is, stars that share similar velocity components. The reasons why some stars move together may be different and are related to dynamical processes connected to the Galaxy, both internal as well as external ones, such as resonances with the Galactic bar or the Galactic spiral arm structure, dissolution of open clusters, or merger events with other galaxies. LÄS MER