hip-20171

Its story

53 Tauri is a chemically peculiar mercury-manganese (HgMn) star —a very rare class in which mercury, manganese and other heavy elements concentrate anomalously in its atmosphere through gravitational settling—. In its particular case, however, the diagnostic ionized-mercury line at 398.4 nm is strangely absent, making it an anomaly within an already rare group. It forms a spectroscopic binary system 270 light-years away in the northern half of Taurus.