High resolution spectra obtained from the Subaru Telescope High Dispersion Spectrograph have been used to update the stellar atmospheric parameters and metallicity of the star HD 209621 .
We have derived a metallicity of { [ Fe / H ] } = -1.93 for this star , and have found a large enhancement of carbon and of heavy elements , with respect to iron .
Updates on the elemental abundances of four s-process elements ( Y , Ce , Pr , Nd ) along with the first estimates of abundances for a number of other heavy elements ( Sr , Zr , Ba , La , Sm , Eu , Er , Pb ) are reported .
The stellar atmospheric parameters , the effective temperature , T _ { eff } , and the surface gravity , log g ( 4500 K , 2.0 ) , are determined from LTE analysis using model atmospheres .
Estimated [ Ba/Eu ] = +0.35 , places the star in the group of CEMP- ( r+s ) stars ; however , the s-elements abundance pattern seen in HD 209621 is characteristic of CH stars ; notably , the 2nd-peak s-process elements are more enhanced than the first peak s-process elements .
HD 209621 is also found to show a large enhancement of the 3rd-peak s-process element lead ( Pb ) with { [ Pb / Fe ] } = +1.88 .
The relative contributions of the two neutron-capture processes , r- and s- to the observed abundances are examined using a parametric model based analysis , that hints that the neutron-capture elements in HD 209621 primarily originate in s-process .