Sökning: "Oleg Kochukhov"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden Oleg Kochukhov.

  1. 1. 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

  2. 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

  3. 3. Magnetic Fields and Chemical Spots in HgMn Stars

    Författare :Vitalii Makaganiuk; Oleg Kochukhov; Nikolai Piskunov; Gregg Wade; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemically peculiar stars; magnetic fields; spectropolarimetry; Doppler imaging; Astronomy with specialization in Astrophysics; Astronomi med intiktning mot astrofysik;

    Sammanfattning : Mercury-manganese (HgMn) stars belong to the class of chemically peculiar (CP) stars. It was recently discovered that some HgMn stars have spots of chemical elements on their surfaces. LÄS MER

  4. 4. Investigating magnetic fields in the solar chromosphere

    Författare :Alexander Pietrow; Dan Kiselman; Jaime de la Cruz Rodr´ıguez; Oleg Kochukhov; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sun; chromosphere; plage; Astronomy; astronomi;

    Sammanfattning : Solar plage has been the topic of many studies since its initial description in the mid 19th century, but as of yet it has not been understood to the point where we can reproduce all aspects of these active regions in quasi-realistic numerical models. To a large extent, this is caused by an incomplete understanding of the magnetic structure that drives the activity in these areas. LÄS MER

  5. 5. 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