Essays about: "Stellar spectra"

Showing result 1 - 5 of 50 essays containing the words Stellar spectra.

1. 1. Measuring copper abundances in the Galactic Bulge

   University essay from Lunds universitet/Astrofysik; Lunds universitet/Fysiska institutionen

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

   Abstract : 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. READ MORE

3. 2. Wavelength-dependent limb darkeningin the analysis oftransit spectroscopy of exoplanets

   University essay from Uppsala universitet/Institutionen för fysik och astronomi

   Author : Alberto García Ribas; [2023]
   Keywords : ;

   Abstract : Limb darkening, an optical effect characteristic of stars, where the limb (edge) seemsto be darker than the centre of the stellar body; plays an important role in our under-standing of exoplanetary transits, as it is fundamental for developing light curve modelsthat can help to undercover extrasolar companions. To recover atmospheric featuresfrom exoplanets, a principal component analysis method is typically used. READ MORE

4. 3. Potassium in the Galactic Bulge - as traced by microlensed dwarf & sub-giant stars

   University essay from Lunds universitet/Astrofysik; Lunds universitet/Fysiska institutionen

   Author : Lukas Jönsson; [2023]
   Keywords : Nucleosynthesis; Galactic Bulge; Potassium; Non-Local-Thermal-Equilibrium; Physics and Astronomy;

   Abstract : During this report the potassium (K) trend in the Galactic Bulge, with respect to metallicity and various α-elements, has been computed and evaluated by a method of line synthesis on the 7698.96 ̊A KI line (7699 KI), where Non-Local-Thermal-Equilibrium (NLTE) effects have been considered. READ MORE

5. 4. Magnetic field of the magnetic chemically peculiar star V1148 Ori

   University essay from Uppsala universitet/Institutionen för fysik och astronomi

   Author : Kristoffer Pettersson; [2023]
   Keywords : chemically peculiar star; magnetic fields; deconvolution; zeeman effect; polarization;

   Abstract : This project aims to obtain and interpret the measurements of the mean longitudinal magnetic field of the chemically peculiar star V1148 Ori. To achieve this aim 12 spectropolarimetric observations obtained by the CFHT using the spectropolarimeter ESPaDOnS were used. READ MORE

6. 5. The chemical evolution of the Milky Way: pushing APOGEE to higher precision and accuracy

   University essay from Lunds universitet/Astrofysik; Lunds universitet/Fysiska institutionen

   Author : Erik Fridén; [2023]
   Keywords : Physics and Astronomy;

   Abstract : In the recent decade, a rapid increase in all-sky spectroscopic surveys has occurred, and with it, the wealth of observational data and information on our Galaxy. Consequently, numerous detections of new structures, such as new open clusters, accreted and in-situ components, are discovered. READ MORE