We present an abundance analysis of the very metal-poor , carbon-enhanced star CS 29497-030 .
Our results indicate that this unusually hot turnoff star ( T _ { eff } = 6650 K , log g = 3.5 ) has a metallicity [ Fe/H ] = -2.8 , and exhibits large overabundances of carbon ( [ C/Fe ] = +2.38 ) , nitrogen ( [ N/Fe ] = +1.88 ) , and oxygen ( [ O/Fe ] = +1.67 ) .
This star also exhibits a large enhancement in its neutron-capture elements ; the pattern follows that expected to arise from the s - process .
In particular , the Pb abundance is found to be very high with respect to iron ( [ Pb/Fe ] = +3.5 ) , and also with respect to the second peak s -process elements ( e.g. , Ba , La , Ce , Nd ) , which fits into the newly introduced classification of lead ( Pb ) stars .
The known spectroscopic binary status of this star , along with the observed s -process abundance pattern , suggest that it has accreted matter from a companion , which formerly was an Asymptotic Giant-Branch ( AGB ) star .
In a preliminary analysis , we have also identified broad absorption lines of metallic species that suggest a large axial rotational velocity for this star , which may be the result of spin-up associated with the accretion of material from its previous AGB companion .
In addition , this star is clearly depleted in the light element Li .
When considered along with its rather high inferred temperature , these observations are consistent with the expected properties of a very low metallicity halo blue straggler .