Origin of phosphorus-rich (P-rich) stars

Determine the stellar evolutionary pathways and nucleosynthetic sites that produce phosphorus-rich stars—ancient, metal-poor giants with phosphorus abundances an order of magnitude above solar—in order to reconcile observations with Galactic chemical evolution models.

Background

The authors summarize prior work showing that some stars exhibit phosphorus abundances far exceeding standard Galactic chemical evolution predictions, including a class of phosphorus-rich (P-rich) stars with ~10× solar phosphorus. These objects are typically old, metal-poor giants.

The paper notes that the origin of such P-rich stars is not explained by current models and may imply either incomplete understanding of neutron-capture nucleosynthesis yields or the presence of additional astrophysical sites for phosphorus production.