Sökning: "Stjärnor"

Visar resultat 6 - 10 av 145 uppsatser innehållade ordet Stjärnor.

  1. 6. What limits the luminosity of red supergiants?

    Kandidat-uppsats, Lunds universitet/Astrofysik; Lunds universitet/Fysiska institutionen

    Författare :Eric Svensson; [2023]
    Nyckelord :Stellar evolution; Red supergiants; Red giants; Luminosity; Binary stars; Binary star systems; Binary star interactions; Binary stellar evolution; Humphreys-Davidson limit; Upper luminosity limit; BSE; Population synthesis; Simulations; M31; LMC; SMC; Metallicity; Mass transfer; Merging; Physics and Astronomy;

    Sammanfattning : The observed upper limit of the luminosity of red supergiants, often called the Humphreys-Davidson limit, has recently been shown to be independent of metallicity and to not be explainable by single star evolution – findings that both contradict established ideas of the origins of the limit. It is now known that the vast majority of stars with sufficient mass to possibly evolve into red supergiants above the limit interact with companion stars at some point during their lives. LÄS MER

  2. 7. Svenska gymnasieelevers uppfattningar om storlek och avstånd i universum

    Uppsats för yrkesexamina på avancerad nivå, Lunds universitet/Fysiska institutionen; Lunds universitet/Institutionen för utbildningsvetenskap

    Författare :Karolin Nilsson; [2023]
    Nyckelord :Astronomy; Misconceptions; Educational Research; Science Education; High School Students; Physics and Astronomy;

    Sammanfattning : This study aims to investigate how students in Swedish upper secondary school conceptualize sizes and distances of some astronomical objects, such as planets and stars, as well as the students’ general knowledge of the objects themselves. The study uses a constructivist framework and explores how well the students’ conceptions match the scientific facts and definitions, and what misconceptions and alternative conceptions they hold. LÄS MER

  3. 8. The tangled Warp of the Milky Way

    Master-uppsats, Lunds universitet/Astrofysik; Lunds universitet/Fysiska institutionen

    Författare :Viktor Hrannar Jónsson; [2023]
    Nyckelord :Galaxy: structure; Galaxy: kinematics and dynamics; Galaxy: disk; Galaxy: evolution; Physics and Astronomy;

    Sammanfattning : Context: The Milky Way disc, like the discs of many other spiral galaxies, has been shown to be warped. The growing astrometric data set for stars produced by the Gaia mission allows for more detailed studies of the stellar disc's warp. LÄS MER

  4. 9. Intermediate-mass black hole binary as an origin of super-massive black holes

    Kandidat-uppsats, Lunds universitet/Astrofysik; Lunds universitet/Fysiska institutionen

    Författare :Isabelle Signe Maj Maria Thord; [2023]
    Nyckelord :Intermediate-mass black holes; binary; merger; hardening; encounters; Physics and Astronomy;

    Sammanfattning : Galactic nuclei contain super-massive black holes (SMBHs), nuclear stellar clusters (NSCs), or both. In the NSC, intermediate-mass black holes (IMBHs) are likely to reside and form highly eccentric binaries. Over time, the orbit of a binary could harden via interaction with surrounding low-mass stars. LÄS MER

  5. 10. Void Evolution and Cosmic Star Formation

    Kandidat-uppsats, Uppsala universitet/Institutionen för fysik och astronomi

    Författare :Joel Wasserman; [2023]
    Nyckelord :Void; Void Evolution; Cosmic Void; Star Formation Rate; Star Formation History; Cosmic Star Formation; Cosmology; Spherical Evolution Model; SvdW; Vdn; Excursion Set Theory; Excursion Set Formalism; Astrophysics; Astronomy; Cosmic Web; Matter Transfer; Tomrum; Tomrumsutveckling; Kosmiska Tomrum; Stjärnbildningshastighet; Stjärnbildningshistorik; Kosmisk stjärnbildning; Kosmologi; Sfärisk Evolutionsmodell; SvdW; Vdn; Exkursionsset teori; Exkursionsset Formalism; Astrofysik; Astronomi; Kosmiska Spindelnätet; Masstransport;

    Sammanfattning : The rate at which stars have formed throughout the history of theuniverse is not constant, it started out slow, increased until around redshift ∼ 2 when it reversed and became slower again. The reason for this behaviour is still being investigated with various models and simulations usually based upon dark matter halos. LÄS MER