  We measured phosphorus abundances in 22 FGK dwarfs and giants that span
--0.55 $<$ [Fe/H] $<$ 0.2 using spectra obtained with the Phoenix high
resolution infrared spectrometer on the Kitt Peak National Observatory Mayall
4m telescope, the Gemini South Telescope, and the Arcturus spectral atlas. We
fit synthetic spectra to the P I feature at 10581 $\AA$ to determine abundances
for our sample. Our results are consistent with previously measured phosphorus
abundances; the average [P/Fe] ratio measured in [Fe/H] bins of 0.2 dex for our
stars are within $\sim$ 1 $\sigma$ compared to averages from other IR
phosphorus studies. Our study provides more evidence that models of chemical
evolution using the results of theoretical yields are under producing
phosphorus compared to the observed abundances. Our data better fit a chemical
evolution model with phosphorus yields increased by a factor of 2.75 compared
to models with unadjusted yields. We also found average [P/Si] = 0.02 $\pm$
0.07 and [P/S] = 0.15 $\pm$ 0.15 for our sample, showing no significant
deviations from the solar ratios for [P/Si] and [P/S] ratios.

Solar and Stellar Astrophysics