Sökning: "himlavalvet"

Visar resultat 1 - 5 av 9 uppsatser innehållade ordet himlavalvet.

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. 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

4. 3. Towards a high resolution view of infrared line formation

   Master-uppsats, Lunds universitet/Astronomi - Genomgår omorganisation

   Författare :Martin Schmidt Montelius; [2021]
   Nyckelord :Spectroscopy; Near infrared; K giants; Galactic archeaology; Galactic chemical evolution; Abundances; Milky Way; Physics and Astronomy;

   Sammanfattning : Observing in the infrared has many benefits, such as seeing through the interstellar dust in the galaxy, easier use of adaptive optics, and better flux ratios for direct observations of exoplanets. Before the infrared spectral range can be utilised for highly accurate stellar spectroscopy there is a need for a better understanding of both stellar modelling and the atomic physics that go into forming spectral lines. LÄS MER

5. 4. Konstruktion av solföljare med LDR och GPS : Självständigt arbete i teknisk fysik

   Kandidat-uppsats, Uppsala universitet/Institutionen för elektroteknik

   Författare :Albin Strid; Love Magnusson; [2021]
   Nyckelord :Solpanel; solföljare; arduino; gps; ldr;

   Sammanfattning : Världen är i behov av en ständigt ökande mängd energi och även om vi kan fortsätta att skövla regnskogarna och ödelägga haven i jakt på olja så är detta inte en hållbar lösning. Mer förnybar energi behöver produceras och detta kan åstadkommas genom att antingen utökningen av de nuvarande förnybara energikällorna eller genom att utveckla mer effektiva sätt att generera förnybar energi. LÄS MER

7. 5. Large Surveys and Data-Driven Investigations of Radial Migration

   Master-uppsats, Lunds universitet/Astronomi - Genomgår omorganisation

   Författare :John Bradley Bowers; [2019]
   Nyckelord :Physics and Astronomy;

   Sammanfattning : We probe the implications of 5 different previously developed models of the evolution of the Milky Way’s radial metallicity gradient for radial migration of stars observed today between 5kpc < R < 12kpc. Our sample contains 7167 giant stars, with metallicities and radial velocities obtained from APOGEE DR14, full 5-parameter kinematic information from Gaia DR2, and ages derived in Martig et al. LÄS MER