HD 65949 is a late B star with exceptionally strong Hg II \lambda 3984 , but it is not a typical HgMn star .
The Re II spectrum is of extraordinary strength .
Abundances , or upper limits are derived here for 58 elements based on a model with T _ { eff } = 13100 K , and \log ( g ) = 4.0 .
Even-Z elements through nickel show minor deviations from solar abundances .
Anomalies among the odd-Z elements through copper are mostly small .
Beyond the iron peak , a huge scatter is found .
Enormous enhancements are found for the elements rhenium through mercury ( Z = 75–80 ) . We note the presence of Th III in the spectrum . The abundance pattern of the heaviest elements resembles the N=126 r-process peak of solar material , though not in detail .
An odd-Z anomaly appears at the triplet ( Zr Nb Mo ) , and there is a large abundance jump between Xe ( Z = 54 ) and Ba ( Z = 56 ) .
These are signatures of chemical fractionation .

We find a significant correlation of the abundance excesses with second ionization potentials for elements with Z > 30 .
If this is not a red herring ( false lead ) , it indicates the relevance of photospheric or near-photospheric processes .
Large excesses ( 4-6 dex ) require diffusion from deeper layers with the elements passing through a number of ionization stages .
That would make the correlation with second ionization potential puzzling .
We explore a model with mass accretion of exotic material followed by the more commonly accepted differentiation by diffusion .
That model leads to a number of predictions which challenge future work .

New observations confirm the orbital elements of Gieseking and Karimie , apart from the systemic velocity , which has increased .
Likely primary and secondary masses are near 3.3 and 1.6 M _ { \odot } , with a separation of ca .
0.25 AU .

New atomic structure calculations are presented in two appendices .
These include partition functions for the first through third spectra of Ru , Re , and Os , as well as oscillator strengths in the Re II spectrum .