Przybylski's Star

Przybylski's Star /ʃᵻˈbɪlskiz stɑːr/, or HD 101065, is a rapidly oscillating Ap star that is located at a distance of roughly 370 light-years (110 parsecs) from the Sun in the southern constellation of Centaurus.

In 1961, the Polish-Australian astronomer Antoni Przybylski (Polish pronunciation [ˈantɔɲi pʂɨˈbɨlski]) discovered that this star had a peculiar spectrum that would not fit into the standard framework for stellar classification. Przybylski's observations indicated unusually low amounts of iron and nickel in the star's spectrum, but higher amounts of unusual elements like strontium, holmium, niobium, scandium, yttrium, caesium, neodymium, praseodymium, thorium, ytterbium, and uranium. In fact, at first Przybylski doubted that iron was present in the spectrum at all. Modern work shows that the iron-group elements are somewhat below normal in abundance, but it is clear that the lanthanides and other exotic elements are highly overabundant. Lanthanide elements are from 1000 to 10,000 times more abundant than in the Sun. As a result of these peculiar abundances this star belongs firmly in the Ap star class.