Filtyp
The scientific development of astronomy today mainly comes from the information that can be obtained via electromagnetic radiation. Today, the Gaia optical telescope is one of the most ambitious space projects man has ever completed. Another optical telescope LSST is designed to complement Gaia. In about 15 years it will also be possible to measure gravitational waves with the telescope LISA, whic
In this thesis, I investigate if the binaries that are being tidally disrupted by means of the Hills mechanism, producing hypervelocity stars, could have been transported to the galactic centre by two-body scattering. To survive a scattering event, the binary must be hard, meaning that the binding energy of the binary is higher than the kinetic energy of the collider. If the binary is soft, the bi
The observed high orbital eccentricities of many giant exoplanets is thought to be the result of gravitational scattering between planets. Outcomes of planet-planet scattering can result in some planets being lost by ejections into interstellar space, or collisions between planets or with the star. The likelihood of collisions for a planet with a certain mass, increases with larger radii. After p
The use of reliable distance estimates is key to derive accurate three-dimensional velocities of celestial objects. Systematic overestimation and large uncertainties in the distances will thus provide misleading information of an object's kinematics. In turn, astronomers will get a flawed understanding of dynamical properties of substructures in the Milky Way. In this paper, we employ the imp
The momentum and energy injection from supernovae is one of the main feedback modes, and is therefore key to the understanding of galaxy evolution and star formation. However, due to low resolution, large scale galaxy simulations often have issues with accurately modelling supernovae, and therefore rely on sub-grid models. This is especially true for the injected momentum, where capturing the mome
The aim of this thesis is to find where Hyper Velocity Stars (HVS) originate from. This is done by first finding the HVS, a phenomenon observed in space in which the star has a terminal velocity of more than 1000 km/s. A cross-match of stars will provide the data from two catalogues Gaia and RAVE. Then this data is used to simulate the past trajectory of the HVS and evaluate its origins. One prob
The first planet orbiting a main-sequence star was discovered in 1995. Since then more than 4000 additional exoplanets have been discovered. This is a rapidly evolving field in astrophysics. One of the most common ways to detect an exoplanet is through transit, as the brightness of the host star decreases. The transit method is suitable for surveying a large number of stars at the same time and mo
The Large and Small Magellanic Clouds (LMC & SMC) are the two largest galaxies orbiting the Milky Way (MW). The interactions between them have affected the evolution of both galaxies. The interactions have affected the galaxies differently depending on how strong they have been. Tidal forces from the interactions are argued to have produced a stream of stars and gas called the Magellanic Bridg
Scattered in our galaxy today are planets that have no host star and are only bound to the galaxy. These so called free floating planets are believed to be formed around stars but have later been ejected by passing stars perturbing their orbits, or have undergone close interactions with another planet in a planetary system. This results in one of the planets becoming tightly bound in an often ecce
Thirteen stellar objects known as extended globular clusters were found in the Halo of the Andromeda Galaxy. Three of these extended clusters have quantitative properties which are subsequently used to determine whether clusters of extended size could survive in the orbits of the Milky Way Galaxy. The question of whether extended clusters could survive in the orbits of the Milky Way, is interestin
The usual terrestrial optical astronomy is focused on observing vertically through the atmosphere. When traveling through the atmosphere, the light coming from distant objects gets distorted by the turbulent atmosphere due to varying refractive indices. The effects varies with time and causes position shifts, size changes and intensity variations in an image. The closer to the ground that the ligh
Recent work by Nissen and Schuster have found two distinct populations of halo stars with -1<5 alpha [Fe/H] -0<5. Both populations are kinematically selected to be halo stars. The differences between the two groups are the alpha -elemental abundances and the [Na/Fe] and [Ni/Fe] ratios. From angular momentum space, we can see that the majority of these stars do not show any extreme kinematic indica
Detailed abundance analysis of 41 F and G type dwarf stars located in the solar neighborhood are presented. The stellar sample was selected to have kinematics intermediate between the Galactic thin and thick discs. The stars have been observed with the NOT telescope at La Palma, Spain in March 2006 and the ESO 2.2 m telescope at La Silla, Chile between October 1, 2004 and March 31, 2005. Abundance
