Sökning: "low-mass stars"
Visar resultat 11 - 15 av 16 avhandlingar innehållade orden low-mass stars.
11. Stochastic Chemical Evolution : A Study of Scatter in Relative Elemental Abundances in Extremely Metal-poor Stars
Sammanfattning : Chemical evolution addresses the problem of the formation of the chemical elements and their evolution throughout the history of the universe. This thesis discusses in particular the chemical evolution in the young universe and what we may learn from the observations of the oldest stars. LÄS MER
12. Characterising Young Stellar Binaries
Sammanfattning : Stars are dispersed all over the sky within our Galaxy, appearing in large varieties of ages and sizes. How- ever, estimating said traits proves not to always be trivial, but certain circumstances allow us to probe the characteristics of stellar binaries. LÄS MER
13. On the origin and evolution of blue compact galaxies
Sammanfattning : This thesis is focused on the origin and evolution of blue compact galaxies (BCGs). BCGs are low mass galaxies characterised by blue colours, low chemical abundances and high star formation rates. The gas consumtion time scale is considerable shorter than the age of the universe and thus the high star formation rate must be transient. LÄS MER
14. SN 2011dh and the progenitors of Type IIb supernovae
Sammanfattning : Core-collapse supernovae (SNe) are the observed events following the collapse of the core of evolved massive stars. The gravitational energy released creates a powerful shock that disrupts the star and ejects the heated material into the surrounding circumstellar medium. The observed properties depend on the mass lost by the star, e.g. LÄS MER
15. Formation of Pebble-Pile Planetesimals and the Interior Structure of Comets
Sammanfattning : Planets form in protoplanetary discs of gas, dust and ice around newborn stars. In the Solar System, not only planets are found as a result from the time of planet formation, but also remnant planetesimals in the form of asteroids, Kuiper belt objects and comets. Recent observations, e.g. LÄS MER