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
( K, log 3.5) has a metallicity [Fe/H] , 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.

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.