Phosphorus-rich stars with unusual abundances are challenging theoretical predictions

TL;DR

This paper reports the discovery of 15 phosphorus-rich stars with unusual chemical abundances, challenging current stellar nucleosynthesis models and suggesting alternative processes like stellar rotation or advanced nucleosynthesis.

Contribution

It presents the first identification of phosphorus-rich stars with peculiar abundance patterns, highlighting gaps in existing theoretical models of stellar nucleosynthesis.

Findings

Discovered 15 phosphorus-rich stars with unusual element overabundances.

Challenged current models of stellar nucleosynthesis and chemical evolution.

Suggested alternative processes like rotation or convective-reactive nucleosynthesis.

Abstract

Almost all chemical elements have been made by nucleosynthetic reactions in various kind of stars and have been accumulated along our cosmic history. Among those elements, the origin of phosphorus is of extreme interest because it is known to be essential for life such as we know on Earth. However, current models of (Galactic) chemical evolution under-predict the phosphorus we observe in our Solar System. Here we report the discovery of 15 phosphorus-rich stars with unusual overabundances of O, Mg, Si, Al, and Ce. Phosphorus-rich stars likely inherit their peculiar chemistry from another nearby stellar source but their intriguing chemical abundance pattern challenge the present stellar nucleosynthesis theoretical predictions. Specific effects such as rotation or advanced nucleosynthesis in convective-reactive regions in massive stars represent the most promising alternatives to explain the existence of phosphorus-rich stars. The phosphorus-rich stars progenitors may significantly contribute to the phosphorus present on Earth today.