Alexander Obradovic

Alumni

Monash University

Biography

During my honours project I plan to use archival data to search for undiscovered ultra metal-poor stars (UMP; [Fe/H] < -4), and other stars that are chemically anomalous. These kinds of stars are extremely rare. Ultra metal-poor stars are local relics of the high redshift Universe. The research aims to improve our understanding of UMPs chemical origin and better probe the chemical composition of the Milky Way during its formation period. To do this I will use machine learning techniques to determine stellar parameters for upwards of 25 million stellar spectra and potentially extend the catalogue of UMP and anomalous stars significantly. As part of this work I will search for stars that have anomalous chemical abundance patterns. Examples include Hg-Mn stars: textbook examples of the competing effects of gravity and radiative pressure, where observations have shown abundance variations of six orders of magnitude between comparable stars (i.e. similar mass, luminosity).This projects science objectives and desired outcomes align heavily with the research goals of ASTRO3D. In particular, the “Origin of the Elements” research theme, and the First Stars project. In the coming year we will be directly investigating the pathways for nucleosynthesis over the evolution of the universe and during the formation of the Milky Way. As a result this will require us to develop tools to combat and utilise the enormous amount of data being produce by astronomical instruments.