Sökning: "Binary star systems"

Visar resultat 1 - 5 av 17 uppsatser innehållade orden Binary star systems.

1. 1. 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

3. 2. Origin of blue straggler stars in the Milky Way halo

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

   Författare :Adam Brcek; [2023]
   Nyckelord :Blue Straggler; Galactic Halo; Spectroscopic Surveys; Binary Star Evolution; Mass Transfer; Physics and Astronomy;

   Sammanfattning : Blue straggler stars (BSSs) are exotic stellar objects that appear to be younger than the age of the population they come from suggests. They are observed as the extension of the main sequence stars, beyond the turn-off point. LÄS MER

4. 3. Atomic Structure Calculations Using Configuration-Interaction And Many-Body Perturbation Theory For Spectral Modelling Of Neutron Star Mergers : Example Of Ce I - Iv

   L3-uppsats, Uppsala universitet/Teoretisk fysik

   Författare :Fredrik Plane; [2023]
   Nyckelord :Computational atomic physics; Atomic physics; Physics; Astronomy; Astrophysics; Neutron stars; Stars; Relativisitc atomic physics; Configuration-interaction; Perturbation theory; Many-body perturbation theory;

   Sammanfattning : The binary neutron star merger of 2017 and its corresponding electromagnetic signature resembling that of a kilonova has been one of the most groundbreaking astrophysical occurrences in the last decade. Indications of r-process nucleosynthesis in this event presents new opportunities for learning about the astrophysical origin of heavy elements. LÄS MER

5. 4. Combining Hipparcos and Gaia data: Improved Astrometric Calculations With Orvara

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

   Författare :Melvin Tham; [2023]
   Nyckelord :Astrometry; Af Leporis; Smethells 119; Gliese 105; Gliese 86; Orvara; Hipparcos; Gaia; Physics and Astronomy;

   Sammanfattning : Hipparcos and Gaia are two missions intended to catalogue positions and motions of stellar objects. Orvara is a computer program which aims to combine the data from these two missions to calculate Keplerian parameters for stellar systems. LÄS MER

7. 5. Black Hole Dynamics in Stellar Clusters

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

   Författare :Markus Strickert; [2022]
   Nyckelord :Black Holes; Globular Clusters; Dynamics; Intermediate-mass black holes; Simulations; Physics and Astronomy;

   Sammanfattning : Star clusters can harbour many exotic objects, including black holes (BHs), X-ray binaries and blue straggler stars. In dense stellar environments like globular clusters (GCs), two-body relaxation drives their dynamical evolution, where gravitational interactions between stars strive to equalize their kinetic energy in the cluster. LÄS MER