Very metal-poor stars are of obvious importance for many problems in chemical evolution , star formation , and galaxy evolution .
Finding complete samples of such stars which are also bright enough to allow high-precision individual analyses is of considerable interest .
We demonstrate here that stars with iron abundances [ Fe/H ] < -2 Â dex , and down to below -4 Â dex , can be efficiently identified within the Radial Velocity Experiment ( RAVE ) survey of bright stars , without requiring additional confirmatory observations .
We determine a calibration of the equivalent width of the Calcium triplet lines measured from the RAVE spectra onto true [ Fe/H ] , using high spectral resolution data for a subset of the stars .
These RAVE iron abundances are accurate enough to obviate the need for confirmatory higher-resolution spectroscopy .
Our initial study has identified 631 stars with [ Fe/H ] \leq - 2 , from a RAVE database containing approximately 200,000 stars .
This RAVE-based sample is complete for stars with [ Fe/H ] \lesssim - 2.5 , allowing statistical sample analysis .
We identify three stars with [ Fe/H ] \lesssim - 4 .
Of these , one was already known to be ‘ ultra metal-poor ’ , one is a known carbon-enhanced metal-poor star , but we obtain [ Fe/H ] = -4.0 , rather than the published [ Fe/H ] = -3.3 , and derive [ C/Fe ] = +0.9 , and [ N/Fe ] = +3.2 , and the third is at the limit of our S/N .
RAVE observations are on-going and should prove to be a rich source of bright , easily studied , very metal-poor stars .