Sökning: "red giants"

Visar resultat 1 - 5 av 10 uppsatser innehållade orden red giants.

  1. 1. The visibility of stellar transients in the Galactic Centre

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

    Författare :Jonathan Ström; [2024]
    Nyckelord :Physics and Astronomy;

    Sammanfattning : A semi-analytical simulation was developed to evaluate the K-band magnitudes of Red Giants [0.96 - 1.02 M⊙] orbiting the supermassive black hole in the galactic centre. The model assumed star formation between 10-12 Gyrs ago and by following the IMF and applying a random age condition, a stellar population was created. LÄS MER

  2. 2. Measuring copper abundances in the Galactic Bulge

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

    Författare :Nikolei Höglinger; [2024]
    Nyckelord :Copper; Galaxy: abundances; Galaxy: bulge; Chemical Evolution; Physics and Astronomy;

    Sammanfattning : Context: The chemical evolution of Cu in the Galactic bulge have been studied in a few studies using red giant branch stars, but the ages of individual red giant stars are difficult to determine. In addition, the bulge has been a challenging region of the Milky Way galaxy to obtain high-resolution spectra of stars, except when observing through certain few small fields into the bulge that are known to have low extinction. LÄS MER

  3. 3. 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

  4. 4. Simulations of the Tenuous Upper Atmospheres of Exoplanets

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

    Författare :Lucian Spitzner; [2023]
    Nyckelord :astronomy; astrophyics; exoplanets; transmission spectroscopy; magnetic fields; atmospheres; ions; Physics and Astronomy;

    Sammanfattning : Over the last decade, the interest in research on extraterrestrial planets has expanded dramatically. With the number of confirmed exoplanets having increased tenfold over the last ten years, we now know that many different types of exoplanets exist. LÄS MER

  5. 5. An Infrared Stellar Thermometer

    Kandidat-uppsats, Lunds universitet/Astronomi - Genomgår omorganisation

    Författare :Ieva Puspure; [2021]
    Nyckelord :Infrared Spectroscopy; Infrared; Red giants; Stellar Temperature; Spectroscopy; Physics and Astronomy;

    Sammanfattning : Infrared (IR) spectroscopy has many advantages over optical, one of which is allowing us to see through intergalactic dust, letting us probe deeper into space and dust-dense regions such as galactic centers. However the investigating the IR spectral range is a relatively new field, owing to recent developments in detector technology, and stellar parameter determination in IR is not well researched. LÄS MER