Search for dissertations about: "Astronomi"

Showing result 1 - 5 of 405 swedish dissertations containing the word Astronomi.

  1. 1. The faintest stars : A study of white, red and brown dwarfs

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Leif Festin; [1998]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Astronomy; brown dwarfs; white dwarfs; M dwarf; low luminosity; luminosity function; mass function; Pleiades; Astronomi; NATURAL SCIENCES Physics Astronomy and astrophysics; NATURVETENSKAP Fysik Astronomi och astrofysik; astronomi; Astronomy;

    Abstract : The local space density of the faintest stars, including M dwarfs, white dwarfs and brown dwarfs has been studied by two different methods.By using dark nebulae as opaque outer screens, the luminosity functions of M dwarfs and white dwarfs were studied as volume-limited and dynamically unbiassed foreground samples. READ MORE

  2. 2. Gas Production in Distant Comets

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Marcus Gunnarsson; F Peter Schloerb; [2002]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Astronomy; Comets; Radio Astronomy; Molecular Spectroscopy; Coma Models; Astronomi; NATURAL SCIENCES Physics Astronomy and astrophysics; NATURVETENSKAP Fysik Astronomi och astrofysik; astronomi; Astronomy;

    Abstract : Molecular spectroscopy at radio wavelengths is a tool well suited for studying the composition and outgassing kinematics of cometary comae. This is particularly true for distant comets, i.e. comets at heliocentric distances greater than a few AU, where the excitation of molecules is inefficient other than for rotational energy levels. READ MORE

  3. 3. A study of possible chemical inhomogeneities of dwarf irregular galaxies and the influence on the Z-L relationship

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Ana Maria Hidalgo-Gámez; [1999]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Astronomy; dwarf irregular galaxies; chemical abundances; metallicity-luminosity relationship; individual galaxies: NGC 6822; IC 4662; IC 10; ESO 245-G05; NGC 1569; IC 5152; DDO 53 and DDO 190; Astronomi; NATURAL SCIENCES Physics Astronomy and astrophysics; NATURVETENSKAP Fysik Astronomi och astrofysik; astronomi; Astronomy;

    Abstract : A study on the chemical abundances of dwarf irregular galaxies (dI's) is presented in this work. This type of galaxies have typically low metallicity. First of all, a definition of dI is proposed, in order to obtain a homogeneous group of targets. READ MORE

  4. 4. Thermal physics of asteroids

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Johan S. V. Lagerros; [1998]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Astronomy; asteroids; infrared emission; thermophysical models; Astronomi; NATURAL SCIENCES Physics Astronomy and astrophysics; NATURVETENSKAP Fysik Astronomi och astrofysik; astronomi; Astronomy;

    Abstract : The thermal infrared and microwave emission from asteroids have many applications. Fundamental physical properties can be investigated, which have implications for the geophysical evolution of the asteroids, and the early history of the solar system.A new thermophysical model of asteroids is presented. READ MORE

  5. 5. The Dynamical Spin Vector Evolution of the Asteroids

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Erik Skoglöv; Karri Muinonen; [2002]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Astronomy; asteroids; Eros; Ceres; Vesta; dynamics; rotation; rotational dynamics; orbits; resonances; Astronomi; NATURAL SCIENCES Physics Astronomy and astrophysics; NATURVETENSKAP Fysik Astronomi och astrofysik; astronomi; Astronomy;

    Abstract : The dynamical evolution of the spin axis direction due to gravitational and thermal factors is examined. It is found that the spin axis variations generally are regular and relatively small for the bodies in the asteroid main belt. There are also reasons to believe that this is the case for minor objects beyond the main belt. READ MORE