Sökning: "stellar parameters"

Visar resultat 1 - 5 av 34 uppsatser innehållade orden stellar parameters.

  1. 1. Advanced Characterization of Exoplanet Host Stars

    Master-uppsats, Uppsala universitet/Observationell astrofysik

    Författare :Khaled Al Moulla; [2020]
    Nyckelord :stars: exoplanet hosts - fundamental parameters - spectroscopy: HARPS - SME; stjärnor: exoplanetvärdar - fundamentala parametrar - spektroskopi: HARPS - SME;

    Sammanfattning : The spectroscopic determination of stellar properties is important for subsequent studies of exoplanet atmospheres. In this thesis, HARPS data for 6 exoplanet-hosting, late-type stars is processed to achieve an average signal-to-noise ratio of ~105. LÄS MER

  2. 2. Archaeologic inspection of the Milky Way using vibrations of a fossil : Seismic, spectroscopic and kinematic characterization of a binary metal-poor Halo star

    Kandidat-uppsats, Uppsala universitet/Observationell astrofysik

    Författare :Amanda Byström; [2020]
    Nyckelord :Milky Way; Halo; galactic archaeology; asteroseismology; binary star; CEMP stars; CEMP-r s stars; stellar age; stellar mass; chemical abundance pattern; Gaia-Enceladus; Gaia-Sausage; Sequoia; spectroscopy; metal-poor;

    Sammanfattning : The Milky Way has undergone several mergers with other galaxies during its lifetime. The mergers have been identified via stellar debris in the Halo of the Milky Way. The practice of mapping these mergers is called galactic archaeology. To perform this archaeologic inspection, three stellar features must be mapped: chemistry, kinematics and age. LÄS MER

  3. 3. Analysis of stellar spectra with machine learning

    Master-uppsats, Lunds universitet/Institutionen för teoretisk fysik; Lunds universitet/Astronomi; Lunds universitet/Institutionen för astronomi och teoretisk fysik

    Författare :Alvaro Segovia Otero; [2020]
    Nyckelord :Galactic Archaeology; machine learning; chemical abundances; FGK stars; Physics and Astronomy;

    Sammanfattning : Researchers in the field of Galactic Archaeology have entered the era of industrial revolution. Upcoming surveys are planning on observing tens of millions of stars and high precision and accuracy must be ensured when deriving their stellar parameters and elemental abundances. LÄS MER

  4. 4. Chaos in Stellar Dynamics - Outcomes of Binary-Single interactions in Globular Clusters

    Master-uppsats, Lunds universitet/Astronomi; Lunds universitet/Institutionen för astronomi och teoretisk fysik

    Författare :Lucas Hellström; [2020]
    Nyckelord :Stellar Dynamics; Binary-Single interactions; Dynamical encounters; Additional processes; Physics and Astronomy;

    Sammanfattning : Gravitational encounters between a single star and a binary system can frequently occur in the cores of dense stellar systems like globular clusters. These three-body scattering encounters can lead to a variety of outcomes since the energy of the binary components can be exchanged with the interacting single star. LÄS MER

  5. 5. Identifying Gravitationally Lensed QSO Candidates with eROSITA

    Master-uppsats, Uppsala universitet/Observationell astrofysik

    Författare :Róisín O'Rourke Brogan; [2020]
    Nyckelord :active galactic nuclei; agn; erosita; gaia; gravitational lensing; quasi-stellar objects; strong lensing; multiple images;

    Sammanfattning : As of June 2020, the first all-sky X-ray survey with the eROSITA instrument aboard the spacecraft Spektr-RG has been completed. A high percentage of the 1.1 million objects included in the survey are expected to be active galactic nuclei (AGN). LÄS MER