Bromine ( atomic number Z = 35 ) and antimony ( Z = 51 ) are extremely difficult to detect in stars .
In very few instances , weak and mostly uncertain identifications of Br i , Br ii , and Sb ii in relatively cool , chemically peculiar stars were successful .
Adopted solar abundance values rely on meteoritic determinations .
Here , we announce the first identification of these species in far-ultraviolet spectra of hot stars ( with effective temperatures of 49 500–70 000 K ) , namely in helium-rich ( spectral type DO ) white dwarfs .
We identify the Br vi resonance line at 945.96 Å .
A previous claim of Br detection based on this line is incorrect because its wavelength position is inaccurate by about 7 Å in atomic databases .
Taking advantage of precise laboratory measurements , we identify this line as well as two other , subordinate Br vi lines .
Antimony is detected by the Sb v resonance doublet at 1104.23/1225.98 Å as well as two subordinate Sb vi lines .
A model-atmosphere analysis reveals strongly oversolar Br and Sb abundances that are caused by radiative-levitation dominated atomic diffusion .