What's on tonight at the AAT

Open clusters with HERMES: probing star formation, disruption, stellar evolution and nucleosynthesis

Gayandhi De Silva (Usyd/AAO)

Tonight we use the HERMES spectrograph to study the chemical composition and motions of stars in clusters. These loosely bound "open" clusters within our Milky Way represent the mode in which all stars in the universe are born. These are unique targets as most open clusters disperse into field stars relatively quickly, hence the study of open clusters provide a snap shot of conditions within a star formation event. This project targets broad range of clusters in age, chemical content and location in order to understand their properties across the spectrum. Using this data we can measure about 29 chemical elements and examine the detailed patterns. As HERMES allows 300+ stars it is the most efficient instrument for this study.