Phi

Its story

Phi Herculis is a chemically peculiar star of the mercury-manganese class: its atmosphere holds these heavy metals in concentrations thousands of times richer than the Sun's. To the eye it looks single, but spectrographs uncovered a hidden companion, an A8 star spinning far faster than the primary. It burns blue-white near 10,000 K at 204 light-years, owner of a strange chemistry that still puzzles astrophysicists.