RSAA Colloquia / Seminars / Feast-of-Facts: Friday, 16 December 2016, 14:00-14:20; Duffield Lecture Theatre

Gary Da Costa

"The SkyMapper Search for Extremely Metal Poor Stars"

The filter system employed in the SkyMapper survey of the southern sky incorporates a narrow ’v’ filter centered on the Ca II K-line at 3933Ang, facilitating the identification of extremely metal-poor (EMP) stars in the photometric dataset. A initial survey carried out during telescope commissioning resulted in the discovery of the most iron-poor star known (SMSS J0313-6708) and a further 41 stars with [Fe/H] < -3.0 dex. In this contribution we present initial results from a new search for EMP stars based on the SkyMapper Early Data Release (EDR). The EDR covers ~1/3rd of the southern sky. We will discuss the selection process, possible biases, and initial outcomes from the on-going low resolution spectroscopic follow-up program with the ANU 2.3m telescope at Siding Spring Observatory that is used to define the best candidates for observation at high dispersion.