Search for dissertations about: "astronomi"

Showing result 1 - 5 of 614 swedish dissertations containing the word astronomi.

  1. 1. Regolith Properties of Mercury Derived from Observations and Modelling

    University dissertation from Astronomical Observatory, Department of Astronomy and Space Physics

    Author : Johan Warell; Uppsala universitet.; [2003]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Astronomy; Mercury; Moon; imaging; photometry; spectroscopy; regolith; space weathering; light scattering; spectral modelling; Astronomi; NATURAL SCIENCES Physics Astronomy and astrophysics; NATURVETENSKAP Fysik Astronomi och astrofysik; astronomi; Astronomy;

    Abstract : The properties of Mercury's regolith have been investigated at optical and near-infrared wavelengths with high-resolution imaging, photometric, and spectroscopic observations with the Swedish Vacuum Solar Telescope and the Nordic Optical Telescope. A new global optical map at a spatial resolution of 200 km shows that the well known (from Mariner 10) and poorly known hemispheres are indistinguishable with respect to the distribution, number density, and morphological parameters of bright albedo features. READ MORE

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

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Leif Festin; Uppsala universitet.; [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

  3. 3. Gas Production in Distant Comets

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Marcus Gunnarsson; Uppsala universitet.; [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

  4. 4. 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; Uppsala universitet.; [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

  5. 5. Thermal physics of asteroids

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Johan S. V. Lagerros; Uppsala universitet.; [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