Sökning: "stars: magnetic field"

Visar resultat 1 - 5 av 24 avhandlingar innehållade orden stars: magnetic field.

  1. 1. Magnetic fields of cool active stars

    Författare :Lisa Rosén; Oleg Kochukhov; Eric Stempels; Andrew Collier Cameron; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; stars: magnetic field; stars: late-type; stars: activity; stars: imaging; polarisation; starspots; Astronomy; Astronomi;

    Sammanfattning : 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. LÄS MER

  3. 2. Magnetic fields of cool stars from near-infrared spectropolarimetry

    Författare :Alexis Lavail; Oleg Kochukhov; Nikolai Piskunov; Gaitee Hussain; Jeff Valenti; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; stars: magnetic field; stars: pre-main-sequence; stars: late-type; techniques: spectroscopic; techniques: polarimetric; Astronomy; Astronomi;

    Sammanfattning : Magnetic fields rule many physical processes in and around stars throughout their lifetime. All cool stars possess a magnetic field, likely generated by dynamo processes. In order to properly understand the evolution of cool stars, we need to understand their magnetism. LÄS MER

  4. 3. Unveiling a multi-scale view of massive star and cluster formation

    Författare :Chi Yan Law; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; massive stars; methods:observation; magnetic field; stars:formation; ISM:clouds;

    Sammanfattning : Massive stars regulate the physical and chemical evolution of galaxies. Most stars within these galaxies, including massive ones, appear to be born in star clusters. However, there are many open questions about how these systems form from diffuse interstellar gas. LÄS MER

  5. 4. Magnetic and Chemical Structures in Stellar Atmospheres

    Författare :Oleg Kochukhov; Nikolai Piskunov; Georges Michaud; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Astronomy; chemically peculiar stars; high-resolution spectroscopy; magnetic fields; Doppler imaging; rapidly oscillating Ap stars; Astronomi; Astronomy and astrophysics; Astronomi och astrofysik; Astronomy; Astronomi;

    Sammanfattning : We present an investigation of the magnetic field geometries and inhomogeneous distribution of chemical elements in the atmospheres of peculiar A and B stars. Our study combines high-quality spectroscopic and spectropolarimetric stellar observations with the development and application of novel techniques for theoretical interpretation of the shapes and variability of stellar line profiles. LÄS MER

  7. 5. Magnetic fields and chemical maps of Ap stars from four Stokes parameter observations

    Författare :Naum Rusomarov; Oleg Kochukhov; Nikolai Piskunov; Werner Weiss; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; chemically peculiar stars; magnetic fields; spectropolarimetry; Doppler imaging; stellar atmospheres; Astronomy with specialization in Astrophysics; Astronomi med intiktning mot astrofysik; Astronomy; Astronomi;

    Sammanfattning : Our knowledge of stellar magnetic fields relies almost entirely on circular polarization observations, which has historically limited our understanding of the stellar magnetic field topologies. Recently, it has become possible to obtain phase-resolved high-resolution spectropolarimetric observations in all four Stokes parameters for early-type magnetic stars. LÄS MER