Context :

Aims : The aim of this study is a detailed abundance analysis of the newly discovered r-rich star HE 1405 - 0822 , which has \mathrm { [ Fe / H ] } = -2.40 .
This star shows enhancements of both r- and s-elements , \mathrm { [ Ba / Fe ] } = +1.95 and \mathrm { [ Eu / Fe ] } = 1.54 , for which reason it is called r+s star .

Methods : Stellar parameters and element abundances were determined by analying high-quality VLT/UVES spectra .
We used Fe I line excitation equilibria to derive the effective temperature .
The surface gravity was calculated from the Fe i /Fe ii and Ti i /Ti ii equilibria .

Results : We determined accurate abundances for 39 elements , including 19 neutron-capture elements .
HE 1405 - 0822 is a red giant .
Its strong enhancements of C , N , and s-elements are the consequence of enrichment by a former AGB companion with an initial mass of less than 3 \mathrm { M } _ { \odot } .
The heavy n-capture element abundances ( including Eu , Yb , and Hf ) seen in HE 1405 - 0822 do not agree with the r-process pattern seen in strongly r-process-enhanced stars .
We discuss possible enrichment scenarios for this star .
The enhanced \alpha elements can be explained as the result of enrichment by supernovae of type II .
Na and Mg may have partly been synthesized in a former AGB companion , when the primary ^ { 22 } Ne acted as a neutron poison in the ^ { 13 } C-pocket .

Conclusions :