Sökning: "massive stars"

Visar resultat 21 - 25 av 44 uppsatser innehållade orden massive stars.

1. 21. Carbon Abundance in the Milky Way Galaxy

   Kandidat-uppsats, Lunds universitet/Astronomi - Genomgår omorganisation

   Författare :Calum Kvernes Macpherson; [2021]
   Nyckelord :Carbon; Abundance; Milky Way; Chemical Evolution; Physics and Astronomy;

   Sammanfattning : Carbon is the fourth most abundant element after hydrogen, helium and oxygen. It is a product of stellar nucleosynthesis as well as it being an important bio signature for life; this makes the analysis of carbon very fundamental. LÄS MER

3. 22. Analysis of stellar spectra with machine learning

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

   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. 23. A Close Look at the Transient Sky in a Neighbouring Galaxy

   Master-uppsats, Luleå tekniska universitet/Rymdteknik

   Författare :Kiran Tikare; [2020]
   Nyckelord :Astrophysical Transients; Optical Transients; Microlensing; Variable Stars; Andromeda Galaxy; Forced Aperture Photometry; Time Domain Astronomy; Sky Survey; Zwicky Transient Facility; Machine Learning; Big Data Science;

   Sammanfattning : Study of the time variable sources and phenomena in Astrophysics provides us with important insights into the stellar evolution, galactic evolution, stellar population studies and cosmological studies such as number density of dark massive objects. Study of these sources and phenomena forms the basis of Time Domain surveys, where the telescopes while scanning the sky regularly for a period of time provides us with positional and temporal data of various Astrophysical sources and phenomena happening in the Universe. LÄS MER

5. 24. Stars Eating Planets

   Master-uppsats, Lunds universitet/Astronomi - Genomgår omorganisation

   Författare :John Wimarsson; [2020]
   Nyckelord :Earth and planetary astrophysics; planetary dynamics; planet-planet scattering; planet consumption; Physics and Astronomy;

   Sammanfattning : In a phase of instability during the dynamical evolution of some multiple exoplanetary systems, exchange of angular momentum and/or energy through gravitational interactions between planets will lead to alterations of their orbital properties. In some cases, planetary orbits end up crossing, which leads to close encounters between two planets. LÄS MER

7. 25. Accurate Abundances of Giant Stars in the Local disk: A manual analysis of IR APOGEE spectra

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

   Författare :Ivalu Barlach Christensen; [2020]
   Nyckelord :Galactic Chemical Evolution; Astrophysics; Astronomy; IR Spectroscopy; Milky Way; Abundance; Physics and Astronomy;

   Sammanfattning : Purpose: In order to study the Galactic Chemical Evolution, elemental abundances are needed. The purpose of this work is to investigate the chemical evolution of the Milky Way by determining several elemental abundances of giants in the local disk. LÄS MER