An enigma of Przybylski's star: Is there promethium on its surface?

AbstractWe carried out a new attempt to check for the presence of promethium lines in the spectrum of HD 101065 (Przybylski's star). The neutron capture element promethium does not have stable isotopes, and the maximum half‐life time is about 18 years. Thus, its presence in this peculiar star would indicate an ongoing process of irradiation of its surface layers with free neutrons. Unfortunately, almost all promethium lines are heavily blended with lines of other neutron capture elements and other species. We selected and analyzed three lines of promethium (Pm I and Pm II) and came to the conclusion that at present it is impossible to definitely claim the presence of this element in Przybylski's star atmosphere.