Phosphorus is an important element for the development of life, yet there is uncertainty in its cosmic origins. It is thought to be made during hydrostatic carbon burning during the life-time of massive stars. However, measurements made in stars don’t match chemical evolution models predicting phosphorus abundances in the Galaxy.
To further constrain the deviations from chemical evolution models and understand the production sites of phosphorus we have measured the atomic phosphorus feature at 1.06 $\mu$m in 22 thin disk stars using the Phoenix instrument with the Mayall 4m telescope. Our abundances derived from phosphorus infrared features agree with the results of previous studies and find phosphorus models underestimate abundances measured in the thin disk.