Search for dissertations about: "Stars"

Showing result 1 - 5 of 185 swedish dissertations containing the word Stars.

  1. 1. Solar Type Stars as Calibrators A Photometric and Spectroscopic Study on the Atmospheric Properties of Late-type Stars

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Anna Önehag; Uppsala universitet.; [2011]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; stars: atmospheres; stars: late-type; techniques: photometric; stars: abundances; techniques: spectroscopic; Astronomy; Astronomi;

    Abstract : Detailed knowledge of solar-type stars is essential in the understanding of the evolutionary past, presence and future of the Sun as well as the formation of its planetary system. Moreover, solar-type stars are of key significance for the study of the evolution of the Galaxy. The ages of solar-type stars map the full galactic evolution. READ MORE

  2. 2. Magnetic fields of cool active stars

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Lisa Rosén; Uppsala universitet.; [2016]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; stars: magnetic field; stars: late-type; stars: activity; stars: imaging; polarisation; starspots; Astronomy; Astronomi;

    Abstract : Magnetic fields are present throughout the universe and are very important for many astrophysical processes. Magnetic field influences a star throughout its life and affects nearby objects such as planets. READ MORE

  3. 3. Galactic archaeology with metal-poor stars

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Thomas Nordlander; Uppsala universitet.; [2017]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; stars: abundances; radiative transfer; stars: Population II; stars: Population III;

    Abstract : The chemical fingerprints of old, metal-poor stars can be used to unravel the events of the newborn Universe and help us understand the properties of the first stars and star clusters. The study of nearby stars to infer properties in the distant past is often referred to as Galactic archaeology. READ MORE

  4. 4. Studies of the S-type AGB star W Aquilae : The circumstellar envelope and the fain companion

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Taissa Danilovich; [2013]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; stars: binaries: spectroscopic; circumstellar matter; stars: binaries: visual; stars: evolution; stars: mass-loss; stars: AGB and post-AGB; stars: individual: W Aql;

    Abstract : Low- and intermediate-mass stars will all eventually enter the asymptotic giant branch (AGB) phase. AGB stars experience intense mass-loss, generating a significant fraction of the dust and molecular matter that enrichesthe ISM. AGB stars are also responsible for a the production of about half of all elements heavier than iron. READ MORE

  5. 5. A Study of Grain Drift in C Stars Theoretical Modeling of Dust-Driven Winds in Carbon-Rich Pulsating Giant Stars

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Christer Sandin; Uppsala universitet.; [2003]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Astronomy; hydrodynamics; radiative transfer; instabilities; dust formation; stars: AGB and post-AGB; stars: mass-loss; stars: variables: general; Astronomi; NATURAL SCIENCES Physics Astronomy and astrophysics; NATURVETENSKAP Fysik Astronomi och astrofysik; Theoretical Astrophysics; teoretisk astrofysik;

    Abstract : A major fraction of stars will pass through a short period of dramatic events in their final evolutionary stage. Low- to intermediate-mass stars, studied here, are stripped of their outer parts in a slow massive wind. This mass loss reshapes both the star and the surrounding medium. READ MORE