Use large astrophysical data sets to uncover and characterise young stellar groups near the Sun, revealing how stars form, disperse, and chemically evolve.
Young stars in the solar neighbourhood provide a unique laboratory for understanding how stars and planetary systems form, migrate, and dissolve into the Galactic field. This PhD project builds on the research expertise of Dr Simon Murphy, combining astrometry, photometry, and spectroscopy to identify and characterise young stellar populations within a few hundred parsecs of the Sun. You will exploit high-precision astrometric data from the Gaia space mission, alongside photometric information from the Australian SkyMapper and complementary spectroscopic surveys (e.g. GALAH) to search for co-moving, co-eval groups of stars. Many of these stellar “siblings” are thought to be the dispersed remnants of star-forming regions that have since lost their spatial coherence. By applying modern clustering techniques in phase space and chemical abundance space, the project aims to distinguish genuine young associations from chance alignments and resonant structures. A key focus will be chemical tagging: testing whether stars that formed together share unique chemical fingerprints, even after dynamical mixing. This directly addresses open questions in Galactic archaeology and builds on Dr Murphy’s work on stellar populations and youth diagnostics. The project may also investigate age indicators such as rotation, activity, and lithium absorption to refine membership and age estimates. The project offers an HDR student hands-on training in large-survey data analysis, statistical inference, and stellar astrophysics. The outcomes will improve our census of nearby young stars, inform models of star formation and cluster dissolution, and provide prime targets for future exoplanet and stellar evolution studies.
School of Science
Astronomy | Astrophisics
1892 | 2931
